Re: Stus-List thermostat on 3QM30H > Exhaust Elbow Cleaning
Just posted on other thread YES a real PITA to get to and replace on my 3HM as well $678 bucks later its done ! ouch!! ☹ John Conklin From: CnC-List on behalf of Nauset Beach via CnC-List Sent: Monday, May 28, 2018 10:53:45 AM To: cnc-list@cnc-list.com Cc: Nauset Beach Subject: Re: Stus-List thermostat on 3QM30H > Exhaust Elbow Cleaning Rick &/or anyone else, Is there a recommended “service interval” for checking / cleaning the exhaust elbow on a fresh water cooled 3GM30F? Mine was last checked 3-4 years ago and have probably had 100+ hours operation during that period. It is a real PITA to access / remove / reinstall that elbow. Thanks, Brian From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Rick Brass via CnC-List Sent: Monday, May 28, 2018 10:16 AM To: cnc-list@cnc-list.com Cc: Rick Brass Subject: Re: Stus-List thermostat on 3QM30H Bill; A “raw” water cooled engine passes water from outside the boat ( in your case lake water) through the engine for cooling. A “fresh” water cooled engine has antifreeze in the engine and a heat exchanger, and the lake water only passes through the heat exchanger to cool the antifreeze circulating inside the engine. Josh’s note about making sure you have the correct thermostats installed in your engine is spot on. A raw water engine uses a low temperature thermostat and has a low operating temperature. I would have guesses 120-125, but Josh found a spec of 108 for the thermostat. Your operating temperature when the engine is under load should be around 140-145. That helps to prevent deposits inside the engine that will block the cooling passages. A fresh water engine runs at a higher temperature – diesels are more efficient at higher temperatures. You use a 165 degree thermostat and the engine can get to 180-190 under load. One consequence of the lower temperature in a raw water engine is that there is increased production of unburned hydrocarbons and soot. Back in the day, when I was a Yanmar certified technician and teaching diesel mechanics, the consensus among the mechanics was that the exhaust elbow on the Yanmar 2 and 3 cylinder marine engines should have the carbon buildup cleaned out every 50 to 100 hours – at least yearly – as preventative maintenance. On a raw water engine like yours, that would be a very good idea. Rick Brass Washington, NC ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H
Replaced well paid for replacement Friday of my exhaust elbow on my 82 /37ft yanmar 3HM sure it could not be original but it was full of $#!^ for sure John Conklin From: CnC-List on behalf of Rick Brass via CnC-List Sent: Monday, May 28, 2018 10:15:54 AM To: cnc-list@cnc-list.com Cc: Rick Brass Subject: Re: Stus-List thermostat on 3QM30H Bill; A “raw” water cooled engine passes water from outside the boat ( in your case lake water) through the engine for cooling. A “fresh” water cooled engine has antifreeze in the engine and a heat exchanger, and the lake water only passes through the heat exchanger to cool the antifreeze circulating inside the engine. Josh’s note about making sure you have the correct thermostats installed in your engine is spot on. A raw water engine uses a low temperature thermostat and has a low operating temperature. I would have guesses 120-125, but Josh found a spec of 108 for the thermostat. Your operating temperature when the engine is under load should be around 140-145. That helps to prevent deposits inside the engine that will block the cooling passages. A fresh water engine runs at a higher temperature – diesels are more efficient at higher temperatures. You use a 165 degree thermostat and the engine can get to 180-190 under load. One consequence of the lower temperature in a raw water engine is that there is increased production of unburned hydrocarbons and soot. Back in the day, when I was a Yanmar certified technician and teaching diesel mechanics, the consensus among the mechanics was that the exhaust elbow on the Yanmar 2 and 3 cylinder marine engines should have the carbon buildup cleaned out every 50 to 100 hours – at least yearly – as preventative maintenance. On a raw water engine like yours, that would be a very good idea. Rick Brass Washington, NC From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Josh Muckley via CnC-List Sent: Sunday, May 27, 2018 11:04 AM To: C&C List Cc: Josh Muckley Subject: Re: Stus-List thermostat on 3QM30H Absolutely leave 2 thermostats. I never suggested otherwise. Without a thermostat in one or both of the ports it will act as though the thermostat is wide open all the time providing maximum cooling and the engine will likely never come up to temperature. I was only trying to explain the disparity between your manual and your engine, suggesting that your information (drawings/manual) may have been for the freshwater variant and that because of this disparity you may have also inadvertently installed a thermostat with a freshwater temperature setpoint. Josh On Sun, May 27, 2018, 10:41 AM William Walker via CnC-List mailto:cnc-list@cnc-list.com>> wrote: Josh, Thanks, but I must have older or newer than that diagram (1981 boat). My thermostat housing is on top of exhaust manifold, square in shape with 4 distinct chambers, two of which are machined to accept thermostats.. I think I will just leave as has been for the 7 years I have owned boat. a thermostat in each chamber.. Bill Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List mailto:cnc-list@cnc-list.com>> wrote: Bill, Check out page 162 in the following link. On page 182 it describes the thermostat setpoints. 160 = fresh and 108 =raw. https://drive.google.com/file/d/0B8pEh5lnvP1yenJtR1BxWjhqZGs/view?usp=drivesdk<https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F0B8pEh5lnvP1yenJtR1BxWjhqZGs%2Fview%3Fusp%3Ddrivesdk&data=02%7C01%7C%7C4d3e66f52d0743a10aac08d5c4a5a14e%7C84df9e7fe9f640afb435%7C1%7C0%7C636631138003674934&sdata=BO0vlWCH92gMTQPiy746eYvOYs4fvwZ1FSOwwmbzMEM%3D&reserved=0> Josh On Sun, May 27, 2018, 9:28 AM William Walker via CnC-List mailto:cnc-list@cnc-list.com>> wrote: Josh, I have a drawing from yanmar manual, not quite same as yours. My thermostat cover has bolt pattern different..fore and aft and side to side..I am always confused by "raw water, fresh water" thing...I draw lake water in and through engine and out...no antifreeze or heat exchange..just direct through and out. Bill. Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List mailto:cnc-list@cnc-list.com>> wrote: Is your engine fresh water or raw water cooled. By the model number I'm guessing that it is raw water cooled. I don't have the manuals for the QM series but believe that they are the predecessor to the HM and GM. As such many of the parts are interchangeable and much of the design is the same. In my parts diagrams it shows 2 thermostats but only on the raw later cooled versions of the HM/GM. I'll send you a picture off list. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Sun, May 27, 2018, 8:35 AM Willi
Re: Stus-List thermostat on 3QM30H, Not thermostats
16 years, 3QM30 with a Sendure and one thermostat. No problems. >From my Android... From: CnC-List on behalf of William Walker via CnC-List Sent: Tuesday, May 29, 2018 4:04:12 PM To: cnc-list@cnc-list.com Cc: wwadjo...@aol.com Subject: Re: Stus-List thermostat on 3QM30H, Not thermostats Thanks Paul..I saw the same resources and that is why I only had one new thermostat...lol. I think now I will disassemble and take a harder look at the configuration of the thermostat housing. Bill Sent from AOL Mobile Mail On Tuesday, May 29, 2018 Dreuge via CnC-List wrote: Hi, The thermostat on the raw water cooled Yanmar 3QM30H has always been a bit of a mystery on the use of one thermostat or two thermostats. While there appears to be two thermostat holes in the housing, the service manual shows a diagram of only one thermostat and the discussion is in regards to always "a thermostat". The Yanmar 3QM30 parts manual also lists a quantity of 1 for the thermostat (105582-49200). My engine came with one thermostat, so when I rebuilt the engine, I put in one thermostat and it has been working fine. I wished I took better detailed photos of the thermostat housing, because I recall convincing myself that based on the housing, a second thermostat would would do absolutely nothing. Note for the raw water cooled engine, there is only one thermostat from Yanmar that fits so you can’t screw up and mix thermostats of different temperature settings. Early 3QM30 were converted to fresh water using the Sen-Dure fresh water heat exchange kit. With the Sen-Dure kit, the engine used the same thermostat, but one replaced the temp sender. The engine ran hotter because the heat exchanger was not as optimal in cooling water as exchanging hot for cold raw water. But since the thermostat opened at lower temperature, the engine was not as efficient in coming up to the hotter operating temperature. Later Yanmar came out with the fresh water cooled 3QM30F using Yanmar’s own heat exchanger. The 3QM30F uses a different and physical bigger and hotter thermostat which is mounted on the Yanmar heat exchanger and get rid of the old one which was mounted on top of the exhaust manifold. - Paul E. 1981 C&C 38 Landfall S/V Johanna Rose Fort Walton Beach, FL http://svjohannarose.blogspot.com/ On May 28, 2018, at 9:16 PM, cnc-list-requ...@cnc-list.com<mailto:cnc-list-requ...@cnc-list.com> wrote: Date: Mon, 28 May 2018 20:27:42 -0400 From: wwadjo...@aol.com<mailto:wwadjo...@aol.com> To: cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com> Subject: Re: Stus-List thermostat on 3QM30H Message-ID: <163a94b1b92-c9a-17...@webjas-vab075.srv.aolmail.net<mailto:163a94b1b92-c9a-17...@webjas-vab075.srv.aolmail.net>> Content-Type: text/plain; charset="utf-8" Thanks for info. Sent from AOL Mobile Mail On Monday, May 28, 2018 Rick Brass via CnC-List mailto:cnc-list@cnc-list.com>> wrote: Bill; ? A ?raw? water cooled engine passes water from outside the boat ( in your case lake water) through the engine for cooling. A ?fresh? water cooled engine has antifreeze in the engine and a heat exchanger, and the lake water only passes through the heat exchanger to cool the antifreeze circulating inside the engine. ? Josh?s note about making sure you have the correct thermostats installed in your engine is spot on. ? A raw water engine uses a low temperature thermostat and has a low operating temperature. I would have guesses 120-125, but Josh found a spec of 108 for the thermostat. Your operating temperature when the engine is under load should be around 140-145. That helps to prevent deposits inside the engine that will block the cooling passages. ? A fresh water engine runs at a higher temperature ? diesels are more efficient at higher temperatures. You use a 165 degree thermostat and the engine can get to 180-190 under load. ? One consequence of the lower temperature in a raw water engine is that there is increased production of unburned hydrocarbons and soot. Back in the day, when I was a Yanmar certified technician and teaching diesel mechanics, the consensus among the mechanics was that the exhaust elbow on the Yanmar 2 and 3 cylinder marine engines should have the carbon buildup cleaned out every 50 to 100 hours ? at least yearly ? as preventative maintenance. ? On a raw water engine like yours, that would be a very good idea. ? Rick Brass Washington, NC ? ? ? ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one
Re: Stus-List thermostat on 3QM30H, Not thermostats
Thanks Paul..I saw the same resources and that is why I only had one new thermostat...lol. I think now I will disassemble and take a harder look at the configuration of the thermostat housing. Bill Sent from AOL Mobile Mail On Tuesday, May 29, 2018 Dreuge via CnC-List wrote: Hi, The thermostat on the raw water cooled Yanmar 3QM30H has always been a bit of a mystery on the use of one thermostat or two thermostats. While there appears to be two thermostat holes in the housing, the service manual shows a diagram of only one thermostat and the discussion is in regards to always "a thermostat". The Yanmar 3QM30 parts manual also lists a quantity of 1 for the thermostat (105582-49200). My engine came with one thermostat, so when I rebuilt the engine, I put in one thermostat and it has been working fine. I wished I took better detailed photos of the thermostat housing, because I recall convincing myself that based on the housing, a second thermostat would would do absolutely nothing. Note for the raw water cooled engine, there is only one thermostat from Yanmar that fits so you can’t screw up and mix thermostats of different temperature settings. Early 3QM30 were converted to fresh water using the Sen-Dure fresh water heat exchange kit. With the Sen-Dure kit, the engine used the same thermostat, but one replaced the temp sender. The engine ran hotter because the heat exchanger was not as optimal in cooling water as exchanging hot for cold raw water. But since the thermostat opened at lower temperature, the engine was not as efficient in coming up to the hotter operating temperature. Later Yanmar came out with the fresh water cooled 3QM30F using Yanmar’s own heat exchanger. The 3QM30F uses a different and physical bigger and hotter thermostat which is mounted on the Yanmar heat exchanger and get rid of the old one which was mounted on top of the exhaust manifold. - Paul E. 1981 C&C 38 Landfall S/V Johanna Rose Fort Walton Beach, FL http://svjohannarose.blogspot.com/ On May 28, 2018, at 9:16 PM, cnc-list-requ...@cnc-list.com wrote: Date: Mon, 28 May 2018 20:27:42 -0400 From: wwadjo...@aol.com To: cnc-list@cnc-list.com Subject: Re: Stus-List thermostat on 3QM30H Message-ID: <163a94b1b92-c9a-17...@webjas-vab075.srv.aolmail.net> Content-Type: text/plain; charset="utf-8" Thanks for info. Sent from AOL Mobile Mail On Monday, May 28, 2018 Rick Brass via CnC-List wrote: Bill; ? A ?raw? water cooled engine passes water from outside the boat ( in your case lake water) through the engine for cooling. A ?fresh? water cooled engine has antifreeze in the engine and a heat exchanger, and the lake water only passes through the heat exchanger to cool the antifreeze circulating inside the engine. ? Josh?s note about making sure you have the correct thermostats installed in your engine is spot on. ? A raw water engine uses a low temperature thermostat and has a low operating temperature. I would have guesses 120-125, but Josh found a spec of 108 for the thermostat. Your operating temperature when the engine is under load should be around 140-145. That helps to prevent deposits inside the engine that will block the cooling passages. ? A fresh water engine runs at a higher temperature ? diesels are more efficient at higher temperatures. You use a 165 degree thermostat and the engine can get to 180-190 under load. ? One consequence of the lower temperature in a raw water engine is that there is increased production of unburned hydrocarbons and soot. Back in the day, when I was a Yanmar certified technician and teaching diesel mechanics, the consensus among the mechanics was that the exhaust elbow on the Yanmar 2 and 3 cylinder marine engines should have the carbon buildup cleaned out every 50 to 100 hours ? at least yearly ? as preventative maintenance. ? On a raw water engine like yours, that would be a very good idea. ? Rick Brass Washington, NC ? ? ? ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H, Not thermostats
Hi, The thermostat on the raw water cooled Yanmar 3QM30H has always been a bit of a mystery on the use of one thermostat or two thermostats. While there appears to be two thermostat holes in the housing, the service manual shows a diagram of only one thermostat and the discussion is in regards to always "a thermostat". The Yanmar 3QM30 parts manual also lists a quantity of 1 for the thermostat (105582-49200). My engine came with one thermostat, so when I rebuilt the engine, I put in one thermostat and it has been working fine. I wished I took better detailed photos of the thermostat housing, because I recall convincing myself that based on the housing, a second thermostat would would do absolutely nothing. Note for the raw water cooled engine, there is only one thermostat from Yanmar that fits so you can’t screw up and mix thermostats of different temperature settings. Early 3QM30 were converted to fresh water using the Sen-Dure fresh water heat exchange kit. With the Sen-Dure kit, the engine used the same thermostat, but one replaced the temp sender. The engine ran hotter because the heat exchanger was not as optimal in cooling water as exchanging hot for cold raw water. But since the thermostat opened at lower temperature, the engine was not as efficient in coming up to the hotter operating temperature. Later Yanmar came out with the fresh water cooled 3QM30F using Yanmar’s own heat exchanger. The 3QM30F uses a different and physical bigger and hotter thermostat which is mounted on the Yanmar heat exchanger and get rid of the old one which was mounted on top of the exhaust manifold. - Paul E. 1981 C&C 38 Landfall S/V Johanna Rose Fort Walton Beach, FL http://svjohannarose.blogspot.com/ > On May 28, 2018, at 9:16 PM, cnc-list-requ...@cnc-list.com wrote: > > Date: Mon, 28 May 2018 20:27:42 -0400 > From: wwadjo...@aol.com <mailto:wwadjo...@aol.com> > To: cnc-list@cnc-list.com <mailto:cnc-list@cnc-list.com> > Subject: Re: Stus-List thermostat on 3QM30H > Message-ID: <163a94b1b92-c9a-17...@webjas-vab075.srv.aolmail.net > <mailto:163a94b1b92-c9a-17...@webjas-vab075.srv.aolmail.net>> > Content-Type: text/plain; charset="utf-8" > > Thanks for info. > > Sent from AOL Mobile Mail > > On Monday, May 28, 2018 Rick Brass via CnC-List <mailto:cnc-list@cnc-list.com>> wrote: > > Bill; > > ? > > A ?raw? water cooled engine passes water from outside the boat ( in your case > lake water) through the engine for cooling. A ?fresh? water cooled engine has > antifreeze in the engine and a heat exchanger, and the lake water only passes > through the heat exchanger to cool the antifreeze circulating inside the > engine. > > ? > > Josh?s note about making sure you have the correct thermostats installed in > your engine is spot on. > > ? > > A raw water engine uses a low temperature thermostat and has a low operating > temperature. I would have guesses 120-125, but Josh found a spec of 108 for > the thermostat. Your operating temperature when the engine is under load > should be around 140-145. That helps to prevent deposits inside the engine > that will block the cooling passages. > > ? > > A fresh water engine runs at a higher temperature ? diesels are more > efficient at higher temperatures. You use a 165 degree thermostat and the > engine can get to 180-190 under load. > > ? > > One consequence of the lower temperature in a raw water engine is that there > is increased production of unburned hydrocarbons and soot. Back in the day, > when I was a Yanmar certified technician and teaching diesel mechanics, the > consensus among the mechanics was that the exhaust elbow on the Yanmar 2 and > 3 cylinder marine engines should have the carbon buildup cleaned out every 50 > to 100 hours ? at least yearly ? as preventative maintenance. > > ? > > On a raw water engine like yours, that would be a very good idea. > > ? > > Rick Brass > > Washington, NC > > ? > > ? > > ? ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H
Thanks for info. Sent from AOL Mobile Mail On Monday, May 28, 2018 Rick Brass via CnC-List wrote: Bill; A “raw” water cooled engine passes water from outside the boat ( in your case lake water) through the engine for cooling. A “fresh” water cooled engine has antifreeze in the engine and a heat exchanger, and the lake water only passes through the heat exchanger to cool the antifreeze circulating inside the engine. Josh’s note about making sure you have the correct thermostats installed in your engine is spot on. A raw water engine uses a low temperature thermostat and has a low operating temperature. I would have guesses 120-125, but Josh found a spec of 108 for the thermostat. Your operating temperature when the engine is under load should be around 140-145. That helps to prevent deposits inside the engine that will block the cooling passages. A fresh water engine runs at a higher temperature – diesels are more efficient at higher temperatures. You use a 165 degree thermostat and the engine can get to 180-190 under load. One consequence of the lower temperature in a raw water engine is that there is increased production of unburned hydrocarbons and soot. Back in the day, when I was a Yanmar certified technician and teaching diesel mechanics, the consensus among the mechanics was that the exhaust elbow on the Yanmar 2 and 3 cylinder marine engines should have the carbon buildup cleaned out every 50 to 100 hours – at least yearly – as preventative maintenance. On a raw water engine like yours, that would be a very good idea. Rick Brass Washington, NC From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Josh Muckley via CnC-List Sent: Sunday, May 27, 2018 11:04 AM To: C&C List Cc: Josh Muckley Subject: Re: Stus-List thermostat on 3QM30H Absolutely leave 2 thermostats. I never suggested otherwise. Without a thermostat in one or both of the ports it will act as though the thermostat is wide open all the time providing maximum cooling and the engine will likely never come up to temperature. I was only trying to explain the disparity between your manual and your engine, suggesting that your information (drawings/manual) may have been for the freshwater variant and that because of this disparity you may have also inadvertently installed a thermostat with a freshwater temperature setpoint. Josh On Sun, May 27, 2018, 10:41 AM William Walker via CnC-List wrote: Josh, Thanks, but I must have older or newer than that diagram (1981 boat). My thermostat housing is on top of exhaust manifold, square in shape with 4 distinct chambers, two of which are machined to accept thermostats.. I think I will just leave as has been for the 7 years I have owned boat. a thermostat in each chamber.. Bill Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Bill, Check out page 162 in the following link. On page 182 it describes the thermostat setpoints. 160 = fresh and 108 =raw. https://drive.google.com/file/d/0B8pEh5lnvP1yenJtR1BxWjhqZGs/view?usp=drivesdk Josh On Sun, May 27, 2018, 9:28 AM William Walker via CnC-List wrote: Josh, I have a drawing from yanmar manual, not quite same as yours. My thermostat cover has bolt pattern different..fore and aft and side to side..I am always confused by "raw water, fresh water" thing...I draw lake water in and through engine and out...no antifreeze or heat exchange..just direct through and out. Bill. Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Is your engine fresh water or raw water cooled. By the model number I'm guessing that it is raw water cooled. I don't have the manuals for the QM series but believe that they are the predecessor to the HM and GM. As such many of the parts are interchangeable and much of the design is the same. In my parts diagrams it shows 2 thermostats but only on the raw later cooled versions of the HM/GM. I'll send you a picture off list. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List wrote: Good morning, Yesterday I removed the thermostat cover on top of the exhaust manifold to replace the thermostat which I suspected was bad. I have a yanmar service manual which has detailed drawings of the exhaust manifold on this sea water cooled engine. To my surprise when I removed the cover there were TWO thermostats installed for and aft on starboard side of the exhaust manifold ports. The Yanmar service manual shows only ONE, in the forward port. Since I only had one new thermostat I installed it in the forward port on manifold, cleaned up the other from corrosion and put it back where it was. The second port is machined to accept a thermostat. If you have a yanmar service manual, pictures of this on page 7-A-2 showing one
Re: Stus-List thermostat on 3QM30H > Exhaust Elbow Cleaning
Rick &/or anyone else, Is there a recommended “service interval” for checking / cleaning the exhaust elbow on a fresh water cooled 3GM30F? Mine was last checked 3-4 years ago and have probably had 100+ hours operation during that period. It is a real PITA to access / remove / reinstall that elbow. Thanks, Brian From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Rick Brass via CnC-List Sent: Monday, May 28, 2018 10:16 AM To: cnc-list@cnc-list.com Cc: Rick Brass Subject: Re: Stus-List thermostat on 3QM30H Bill; A “raw” water cooled engine passes water from outside the boat ( in your case lake water) through the engine for cooling. A “fresh” water cooled engine has antifreeze in the engine and a heat exchanger, and the lake water only passes through the heat exchanger to cool the antifreeze circulating inside the engine. Josh’s note about making sure you have the correct thermostats installed in your engine is spot on. A raw water engine uses a low temperature thermostat and has a low operating temperature. I would have guesses 120-125, but Josh found a spec of 108 for the thermostat. Your operating temperature when the engine is under load should be around 140-145. That helps to prevent deposits inside the engine that will block the cooling passages. A fresh water engine runs at a higher temperature – diesels are more efficient at higher temperatures. You use a 165 degree thermostat and the engine can get to 180-190 under load. One consequence of the lower temperature in a raw water engine is that there is increased production of unburned hydrocarbons and soot. Back in the day, when I was a Yanmar certified technician and teaching diesel mechanics, the consensus among the mechanics was that the exhaust elbow on the Yanmar 2 and 3 cylinder marine engines should have the carbon buildup cleaned out every 50 to 100 hours – at least yearly – as preventative maintenance. On a raw water engine like yours, that would be a very good idea. Rick Brass Washington, NC ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H
Bill; A “raw” water cooled engine passes water from outside the boat ( in your case lake water) through the engine for cooling. A “fresh” water cooled engine has antifreeze in the engine and a heat exchanger, and the lake water only passes through the heat exchanger to cool the antifreeze circulating inside the engine. Josh’s note about making sure you have the correct thermostats installed in your engine is spot on. A raw water engine uses a low temperature thermostat and has a low operating temperature. I would have guesses 120-125, but Josh found a spec of 108 for the thermostat. Your operating temperature when the engine is under load should be around 140-145. That helps to prevent deposits inside the engine that will block the cooling passages. A fresh water engine runs at a higher temperature – diesels are more efficient at higher temperatures. You use a 165 degree thermostat and the engine can get to 180-190 under load. One consequence of the lower temperature in a raw water engine is that there is increased production of unburned hydrocarbons and soot. Back in the day, when I was a Yanmar certified technician and teaching diesel mechanics, the consensus among the mechanics was that the exhaust elbow on the Yanmar 2 and 3 cylinder marine engines should have the carbon buildup cleaned out every 50 to 100 hours – at least yearly – as preventative maintenance. On a raw water engine like yours, that would be a very good idea. Rick Brass Washington, NC From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Josh Muckley via CnC-List Sent: Sunday, May 27, 2018 11:04 AM To: C&C List Cc: Josh Muckley Subject: Re: Stus-List thermostat on 3QM30H Absolutely leave 2 thermostats. I never suggested otherwise. Without a thermostat in one or both of the ports it will act as though the thermostat is wide open all the time providing maximum cooling and the engine will likely never come up to temperature. I was only trying to explain the disparity between your manual and your engine, suggesting that your information (drawings/manual) may have been for the freshwater variant and that because of this disparity you may have also inadvertently installed a thermostat with a freshwater temperature setpoint. Josh On Sun, May 27, 2018, 10:41 AM William Walker via CnC-List mailto:cnc-list@cnc-list.com> > wrote: Josh, Thanks, but I must have older or newer than that diagram (1981 boat). My thermostat housing is on top of exhaust manifold, square in shape with 4 distinct chambers, two of which are machined to accept thermostats.. I think I will just leave as has been for the 7 years I have owned boat. a thermostat in each chamber.. Bill Sent from AOL Mobile Mail _ On Sunday, May 27, 2018 Josh Muckley via CnC-List mailto:cnc-list@cnc-list.com> > wrote: Bill, Check out page 162 in the following link. On page 182 it describes the thermostat setpoints. 160 = fresh and 108 =raw. https://drive.google.com/file/d/0B8pEh5lnvP1yenJtR1BxWjhqZGs/view?usp=drivesdk Josh On Sun, May 27, 2018, 9:28 AM William Walker via CnC-List mailto:cnc-list@cnc-list.com> > wrote: Josh, I have a drawing from yanmar manual, not quite same as yours. My thermostat cover has bolt pattern different..fore and aft and side to side..I am always confused by "raw water, fresh water" thing...I draw lake water in and through engine and out...no antifreeze or heat exchange..just direct through and out. Bill. Sent from AOL Mobile Mail _ On Sunday, May 27, 2018 Josh Muckley via CnC-List mailto:cnc-list@cnc-list.com> > wrote: Is your engine fresh water or raw water cooled. By the model number I'm guessing that it is raw water cooled. I don't have the manuals for the QM series but believe that they are the predecessor to the HM and GM. As such many of the parts are interchangeable and much of the design is the same. In my parts diagrams it shows 2 thermostats but only on the raw later cooled versions of the HM/GM. I'll send you a picture off list. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List mailto:cnc-list@cnc-list.com> > wrote: Good morning, Yesterday I removed the thermostat cover on top of the exhaust manifold to replace the thermostat which I suspected was bad. I have a yanmar service manual which has detailed drawings of the exhaust manifold on this sea water cooled engine. To my surprise when I removed the cover there were TWO thermostats installed for and aft on starboard side of the exhaust manifold ports. The Yanmar service manual shows only ONE, in the forward port. Since I only had one new thermostat I installed it in the forward port on manifold, cleaned up the other from corrosion and put it back where it was. The second port is machi
Re: Stus-List thermostat on 3QM30H
Bill, my old 3qm30 had 2 thermostats. My understanding between the raw water cooled and fresh water cooled is the opening temperature of the thermostats. This was from my local Yanmar dealer. Doug Mountjoy Rebecca Leah LF39 POYC, WA. Original message From: William Walker via CnC-List Date: 5/27/18 06:27 (GMT-08:00) To: cnc-list@cnc-list.com Cc: wwadjo...@aol.com Subject: Re: Stus-List thermostat on 3QM30H Josh, I have a drawing from yanmar manual, not quite same as yours. My thermostat cover has bolt pattern different..fore and aft and side to side..I am always confused by "raw water, fresh water" thing...I draw lake water in and through engine and out...no antifreeze or heat exchange..just direct through and out. Bill. Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Is your engine fresh water or raw water cooled. By the model number I'm guessing that it is raw water cooled. I don't have the manuals for the QM series but believe that they are the predecessor to the HM and GM. As such many of the parts are interchangeable and much of the design is the same. In my parts diagrams it shows 2 thermostats but only on the raw later cooled versions of the HM/GM. I'll send you a picture off list. Josh Muckley S/V Sea Hawk 1989 C&C 37+Solomons, MD On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List wrote: Good morning, Yesterday I removed the thermostat cover on top of the exhaust manifold to replace the thermostat which I suspected was bad. I have a yanmar service manual which has detailed drawings of the exhaust manifold on this sea water cooled engine. To my surprise when I removed the cover there were TWO thermostats installed for and aft on starboard side of the exhaust manifold ports. The Yanmar service manual shows only ONE, in the forward port. Since I only had one new thermostat I installed it in the forward port on manifold, cleaned up the other from corrosion and put it back where it was. The second port is machined to accept a thermostat. If you have a yanmar service manual, pictures of this on page 7-A-2 showing one thermostat. Since these two ports are connected internally and water can flow through both I am thinking that this is a safety factor. If one fails the other still may open and allow cooling water to engine. Any thoughts if this second thermostats belongs there? I have been running this engine with it in place for 7 years and I suspect prior owner did as well for a time. Bill Walker Evening Star CnC 36 Pentwater, Mi Sent from AOL Mobile Mail ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H
Got it, thanks for your input... Bill Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Absolutely leave 2 thermostats. I never suggested otherwise. Without a thermostat in one or both of the ports it will act as though the thermostat is wide open all the time providing maximum cooling and the engine will likely never come up to temperature. I was only trying to explain the disparity between your manual and your engine, suggesting that your information (drawings/manual) may have been for the freshwater variant and that because of this disparity you may have also inadvertently installed a thermostat with a freshwater temperature setpoint. Josh On Sun, May 27, 2018, 10:41 AM William Walker via CnC-List wrote: Josh, Thanks, but I must have older or newer than that diagram (1981 boat). My thermostat housing is on top of exhaust manifold, square in shape with 4 distinct chambers, two of which are machined to accept thermostats.. I think I will just leave as has been for the 7 years I have owned boat. a thermostat in each chamber.. Bill Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Bill, Check out page 162 in the following link. On page 182 it describes the thermostat setpoints. 160 = fresh and 108 =raw. https://drive.google.com/file/d/0B8pEh5lnvP1yenJtR1BxWjhqZGs/view?usp=drivesdk Josh On Sun, May 27, 2018, 9:28 AM William Walker via CnC-List wrote: Josh, I have a drawing from yanmar manual, not quite same as yours. My thermostat cover has bolt pattern different..fore and aft and side to side..I am always confused by "raw water, fresh water" thing...I draw lake water in and through engine and out...no antifreeze or heat exchange..just direct through and out. Bill. Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Is your engine fresh water or raw water cooled. By the model number I'm guessing that it is raw water cooled. I don't have the manuals for the QM series but believe that they are the predecessor to the HM and GM. As such many of the parts are interchangeable and much of the design is the same. In my parts diagrams it shows 2 thermostats but only on the raw later cooled versions of the HM/GM. I'll send you a picture off list. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List wrote: Good morning, Yesterday I removed the thermostat cover on top of the exhaust manifold to replace the thermostat which I suspected was bad. I have a yanmar service manual which has detailed drawings of the exhaust manifold on this sea water cooled engine. To my surprise when I removed the cover there were TWO thermostats installed for and aft on starboard side of the exhaust manifold ports. The Yanmar service manual shows only ONE, in the forward port. Since I only had one new thermostat I installed it in the forward port on manifold, cleaned up the other from corrosion and put it back where it was. The second port is machined to accept a thermostat. If you have a yanmar service manual, pictures of this on page 7-A-2 showing one thermostat. Since these two ports are connected internally and water can flow through both I am thinking that this is a safety factor. If one fails the other still may open and allow cooling water to engine. Any thoughts if this second thermostats belongs there? I have been running this engine with it in place for 7 years and I suspect prior owner did as well for a time. Bill Walker Evening Star CnC 36 Pentwater, Mi Sent from AOL Mobile Mail ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurr
Re: Stus-List thermostat on 3QM30H
Absolutely leave 2 thermostats. I never suggested otherwise. Without a thermostat in one or both of the ports it will act as though the thermostat is wide open all the time providing maximum cooling and the engine will likely never come up to temperature. I was only trying to explain the disparity between your manual and your engine, suggesting that your information (drawings/manual) may have been for the freshwater variant and that because of this disparity you may have also inadvertently installed a thermostat with a freshwater temperature setpoint. Josh On Sun, May 27, 2018, 10:41 AM William Walker via CnC-List < cnc-list@cnc-list.com> wrote: > Josh, > Thanks, but I must have older or newer than that diagram (1981 boat). > My thermostat housing is on top of exhaust manifold, square in shape with 4 > distinct chambers, two of which are machined to accept thermostats.. > I think I will just leave as has been for the 7 years I have owned > boat. a thermostat in each chamber.. > Bill > > Sent from AOL Mobile Mail > -- > On Sunday, May 27, 2018 Josh Muckley via CnC-List > wrote: > Bill, > > Check out page 162 in the following link. On page 182 it describes the > thermostat setpoints. 160 = fresh and 108 =raw. > > > https://drive.google.com/file/d/0B8pEh5lnvP1yenJtR1BxWjhqZGs/view?usp=drivesdk > > Josh > > On Sun, May 27, 2018, 9:28 AM William Walker via CnC-List < > cnc-list@cnc-list.com> wrote: > >> Josh, >> I have a drawing from yanmar manual, not quite same as yours. My >> thermostat cover has bolt pattern different..fore and aft and side to >> side..I am always confused by "raw water, fresh water" thing...I draw lake >> water in and through engine and out...no antifreeze or heat exchange..just >> direct through and out. >> Bill. >> >> Sent from AOL Mobile Mail >> -- >> On Sunday, May 27, 2018 Josh Muckley via CnC-List >> wrote: >> Is your engine fresh water or raw water cooled. By the model number I'm >> guessing that it is raw water cooled. I don't have the manuals for the QM >> series but believe that they are the predecessor to the HM and GM. As such >> many of the parts are interchangeable and much of the design is the same. >> In my parts diagrams it shows 2 thermostats but only on the raw later >> cooled versions of the HM/GM. I'll send you a picture off list. >> >> Josh Muckley >> S/V Sea Hawk >> 1989 C&C 37+ >> Solomons, MD >> >> On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List < >> cnc-list@cnc-list.com> wrote: >> >>> Good morning, >>>Yesterday I removed the thermostat cover on top of the exhaust >>> manifold to replace the thermostat which I suspected was bad. I have a >>> yanmar service manual which has detailed drawings of the exhaust manifold >>> on this sea water cooled engine. To my surprise when I removed the cover >>> there were TWO thermostats installed for and aft on starboard side of the >>> exhaust manifold ports. The Yanmar service manual shows only ONE, in the >>> forward port. >>> Since I only had one new thermostat I installed it in the forward port >>> on manifold, cleaned up the other from corrosion and put it back where it >>> was. The second port is machined to accept a thermostat. >>> If you have a yanmar service manual, pictures of this on page 7-A-2 >>> showing one thermostat. >>> Since these two ports are connected internally and water can flow >>> through both I am thinking that this is a safety factor. If one fails the >>> other still may open and allow cooling water to engine. >>> Any thoughts if this second thermostats belongs there? I have been >>> running this engine with it in place for 7 years and I suspect prior owner >>> did as well for a time. >>> Bill Walker >>> Evening Star >>> CnC 36 >>> Pentwater, Mi >>> >>> Sent from AOL Mobile Mail >>> ___ >>> >>> Thanks everyone for supporting this list with your contributions. Each >>> and every one is greatly appreciated. If you want to support the list - >>> use PayPal to send contribution -- https://www.paypal.me/stumurray >>> >>> ___ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - use >> PayPal to send contribution -- https://www.paypal.me/stumurray >> >> ___ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - >> use PayPal to send contribution -- https://www.paypal.me/stumurray >> >> ___ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > > ___
Re: Stus-List thermostat on 3QM30H
Josh, Thanks, but I must have older or newer than that diagram (1981 boat). My thermostat housing is on top of exhaust manifold, square in shape with 4 distinct chambers, two of which are machined to accept thermostats.. I think I will just leave as has been for the 7 years I have owned boat. a thermostat in each chamber.. Bill Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Bill, Check out page 162 in the following link. On page 182 it describes the thermostat setpoints. 160 = fresh and 108 =raw. https://drive.google.com/file/d/0B8pEh5lnvP1yenJtR1BxWjhqZGs/view?usp=drivesdk Josh On Sun, May 27, 2018, 9:28 AM William Walker via CnC-List wrote: Josh, I have a drawing from yanmar manual, not quite same as yours. My thermostat cover has bolt pattern different..fore and aft and side to side..I am always confused by "raw water, fresh water" thing...I draw lake water in and through engine and out...no antifreeze or heat exchange..just direct through and out. Bill. Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Is your engine fresh water or raw water cooled. By the model number I'm guessing that it is raw water cooled. I don't have the manuals for the QM series but believe that they are the predecessor to the HM and GM. As such many of the parts are interchangeable and much of the design is the same. In my parts diagrams it shows 2 thermostats but only on the raw later cooled versions of the HM/GM. I'll send you a picture off list. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List wrote: Good morning, Yesterday I removed the thermostat cover on top of the exhaust manifold to replace the thermostat which I suspected was bad. I have a yanmar service manual which has detailed drawings of the exhaust manifold on this sea water cooled engine. To my surprise when I removed the cover there were TWO thermostats installed for and aft on starboard side of the exhaust manifold ports. The Yanmar service manual shows only ONE, in the forward port. Since I only had one new thermostat I installed it in the forward port on manifold, cleaned up the other from corrosion and put it back where it was. The second port is machined to accept a thermostat. If you have a yanmar service manual, pictures of this on page 7-A-2 showing one thermostat. Since these two ports are connected internally and water can flow through both I am thinking that this is a safety factor. If one fails the other still may open and allow cooling water to engine. Any thoughts if this second thermostats belongs there? I have been running this engine with it in place for 7 years and I suspect prior owner did as well for a time. Bill Walker Evening Star CnC 36 Pentwater, Mi Sent from AOL Mobile Mail ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H
Bill, Check out page 162 in the following link. On page 182 it describes the thermostat setpoints. 160 = fresh and 108 =raw. https://drive.google.com/file/d/0B8pEh5lnvP1yenJtR1BxWjhqZGs/view?usp=drivesdk Josh On Sun, May 27, 2018, 9:28 AM William Walker via CnC-List < cnc-list@cnc-list.com> wrote: > Josh, > I have a drawing from yanmar manual, not quite same as yours. My > thermostat cover has bolt pattern different..fore and aft and side to > side..I am always confused by "raw water, fresh water" thing...I draw lake > water in and through engine and out...no antifreeze or heat exchange..just > direct through and out. > Bill. > > Sent from AOL Mobile Mail > -- > On Sunday, May 27, 2018 Josh Muckley via CnC-List > wrote: > Is your engine fresh water or raw water cooled. By the model number I'm > guessing that it is raw water cooled. I don't have the manuals for the QM > series but believe that they are the predecessor to the HM and GM. As such > many of the parts are interchangeable and much of the design is the same. > In my parts diagrams it shows 2 thermostats but only on the raw later > cooled versions of the HM/GM. I'll send you a picture off list. > > Josh Muckley > S/V Sea Hawk > 1989 C&C 37+ > Solomons, MD > > On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List < > cnc-list@cnc-list.com> wrote: > >> Good morning, >>Yesterday I removed the thermostat cover on top of the exhaust >> manifold to replace the thermostat which I suspected was bad. I have a >> yanmar service manual which has detailed drawings of the exhaust manifold >> on this sea water cooled engine. To my surprise when I removed the cover >> there were TWO thermostats installed for and aft on starboard side of the >> exhaust manifold ports. The Yanmar service manual shows only ONE, in the >> forward port. >> Since I only had one new thermostat I installed it in the forward port on >> manifold, cleaned up the other from corrosion and put it back where it >> was. The second port is machined to accept a thermostat. >> If you have a yanmar service manual, pictures of this on page 7-A-2 >> showing one thermostat. >> Since these two ports are connected internally and water can flow through >> both I am thinking that this is a safety factor. If one fails the other >> still may open and allow cooling water to engine. >> Any thoughts if this second thermostats belongs there? I have been >> running this engine with it in place for 7 years and I suspect prior owner >> did as well for a time. >> Bill Walker >> Evening Star >> CnC 36 >> Pentwater, Mi >> >> Sent from AOL Mobile Mail >> ___ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - >> use PayPal to send contribution -- https://www.paypal.me/stumurray >> >> ___ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H
So your engine IS raw water cooled. This confirms my suspicion that the dual thermostat is part of the raw water design of the HM/GM/QM series. Typically the raw water thermostats run cooler than the fresh. This helps prevent localized boiling and scale formation in the engine. I believe 165°F is normal for raw. 185° or 195° for fresh. You can test them in a pot on the stove top with a thermometer. Josh On Sun, May 27, 2018, 9:28 AM William Walker via CnC-List < cnc-list@cnc-list.com> wrote: > Josh, > I have a drawing from yanmar manual, not quite same as yours. My > thermostat cover has bolt pattern different..fore and aft and side to > side..I am always confused by "raw water, fresh water" thing...I draw lake > water in and through engine and out...no antifreeze or heat exchange..just > direct through and out. > Bill. > > Sent from AOL Mobile Mail > -- > On Sunday, May 27, 2018 Josh Muckley via CnC-List > wrote: > Is your engine fresh water or raw water cooled. By the model number I'm > guessing that it is raw water cooled. I don't have the manuals for the QM > series but believe that they are the predecessor to the HM and GM. As such > many of the parts are interchangeable and much of the design is the same. > In my parts diagrams it shows 2 thermostats but only on the raw later > cooled versions of the HM/GM. I'll send you a picture off list. > > Josh Muckley > S/V Sea Hawk > 1989 C&C 37+ > Solomons, MD > > On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List < > cnc-list@cnc-list.com> wrote: > >> Good morning, >>Yesterday I removed the thermostat cover on top of the exhaust >> manifold to replace the thermostat which I suspected was bad. I have a >> yanmar service manual which has detailed drawings of the exhaust manifold >> on this sea water cooled engine. To my surprise when I removed the cover >> there were TWO thermostats installed for and aft on starboard side of the >> exhaust manifold ports. The Yanmar service manual shows only ONE, in the >> forward port. >> Since I only had one new thermostat I installed it in the forward port on >> manifold, cleaned up the other from corrosion and put it back where it >> was. The second port is machined to accept a thermostat. >> If you have a yanmar service manual, pictures of this on page 7-A-2 >> showing one thermostat. >> Since these two ports are connected internally and water can flow through >> both I am thinking that this is a safety factor. If one fails the other >> still may open and allow cooling water to engine. >> Any thoughts if this second thermostats belongs there? I have been >> running this engine with it in place for 7 years and I suspect prior owner >> did as well for a time. >> Bill Walker >> Evening Star >> CnC 36 >> Pentwater, Mi >> >> Sent from AOL Mobile Mail >> ___ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - >> use PayPal to send contribution -- https://www.paypal.me/stumurray >> >> ___ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H
Josh, I have a drawing from yanmar manual, not quite same as yours. My thermostat cover has bolt pattern different..fore and aft and side to side..I am always confused by "raw water, fresh water" thing...I draw lake water in and through engine and out...no antifreeze or heat exchange..just direct through and out. Bill. Sent from AOL Mobile Mail On Sunday, May 27, 2018 Josh Muckley via CnC-List wrote: Is your engine fresh water or raw water cooled. By the model number I'm guessing that it is raw water cooled. I don't have the manuals for the QM series but believe that they are the predecessor to the HM and GM. As such many of the parts are interchangeable and much of the design is the same. In my parts diagrams it shows 2 thermostats but only on the raw later cooled versions of the HM/GM. I'll send you a picture off list. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List wrote: Good morning, Yesterday I removed the thermostat cover on top of the exhaust manifold to replace the thermostat which I suspected was bad. I have a yanmar service manual which has detailed drawings of the exhaust manifold on this sea water cooled engine. To my surprise when I removed the cover there were TWO thermostats installed for and aft on starboard side of the exhaust manifold ports. The Yanmar service manual shows only ONE, in the forward port. Since I only had one new thermostat I installed it in the forward port on manifold, cleaned up the other from corrosion and put it back where it was. The second port is machined to accept a thermostat. If you have a yanmar service manual, pictures of this on page 7-A-2 showing one thermostat. Since these two ports are connected internally and water can flow through both I am thinking that this is a safety factor. If one fails the other still may open and allow cooling water to engine. Any thoughts if this second thermostats belongs there? I have been running this engine with it in place for 7 years and I suspect prior owner did as well for a time. Bill Walker Evening Star CnC 36 Pentwater, Mi Sent from AOL Mobile Mail ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List thermostat on 3QM30H
Is your engine fresh water or raw water cooled. By the model number I'm guessing that it is raw water cooled. I don't have the manuals for the QM series but believe that they are the predecessor to the HM and GM. As such many of the parts are interchangeable and much of the design is the same. In my parts diagrams it shows 2 thermostats but only on the raw later cooled versions of the HM/GM. I'll send you a picture off list. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Sun, May 27, 2018, 8:35 AM William Walker via CnC-List < cnc-list@cnc-list.com> wrote: > Good morning, >Yesterday I removed the thermostat cover on top of the exhaust manifold > to replace the thermostat which I suspected was bad. I have a yanmar > service manual which has detailed drawings of the exhaust manifold on this > sea water cooled engine. To my surprise when I removed the cover there > were TWO thermostats installed for and aft on starboard side of the exhaust > manifold ports. The Yanmar service manual shows only ONE, in the forward > port. > Since I only had one new thermostat I installed it in the forward port on > manifold, cleaned up the other from corrosion and put it back where it > was. The second port is machined to accept a thermostat. > If you have a yanmar service manual, pictures of this on page 7-A-2 > showing one thermostat. > Since these two ports are connected internally and water can flow through > both I am thinking that this is a safety factor. If one fails the other > still may open and allow cooling water to engine. > Any thoughts if this second thermostats belongs there? I have been > running this engine with it in place for 7 years and I suspect prior owner > did as well for a time. > Bill Walker > Evening Star > CnC 36 > Pentwater, Mi > > Sent from AOL Mobile Mail > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Stus-List thermostat on 3QM30H
Good morning, Yesterday I removed the thermostat cover on top of the exhaust manifold to replace the thermostat which I suspected was bad. I have a yanmar service manual which has detailed drawings of the exhaust manifold on this sea water cooled engine. To my surprise when I removed the cover there were TWO thermostats installed for and aft on starboard side of the exhaust manifold ports. The Yanmar service manual shows only ONE, in the forward port. Since I only had one new thermostat I installed it in the forward port on manifold, cleaned up the other from corrosion and put it back where it was. The second port is machined to accept a thermostat. If you have a yanmar service manual, pictures of this on page 7-A-2 showing one thermostat. Since these two ports are connected internally and water can flow through both I am thinking that this is a safety factor. If one fails the other still may open and allow cooling water to engine. Any thoughts if this second thermostats belongs there? I have been running this engine with it in place for 7 years and I suspect prior owner did as well for a time. Bill Walker Evening Star CnC 36 Pentwater, Mi Sent from AOL Mobile Mail___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
