Pretty sure it's a martec, folding 2-blade. I try to power up and it vibrates like crazy. I power down to try and get it to reset so that I don't damage anything with it vibrating so bad. Then I try again. If I rotate the shaft manually I can hear each blade folding open but for some reason it is tough to open it after sailing for a bit.
Coming out of the slip it opens without a problem. The sounds came this time though while already under power and the prop was open. On Sun, May 27, 2018, 10:27 AM Gary Nylander via CnC-List < [email protected]> wrote: > I’m curious. What kind of prop do you have that requires you to slow down > to get it to open. Most folding ones ask for more speed to get the blades > to open. Non opening would produce lots of vibration, which would get lots > of noise as the engine bounces around on (particularly) old motor mounts. > Shake the motor. > > > > Gary > > Flex-o-fold geared > > > > *From:* CnC-List <[email protected]> *On Behalf Of *Kevin > Paxton via CnC-List > *Sent:* Saturday, May 26, 2018 8:05 PM > *To:* [email protected] > *Cc:* Kevin Paxton <[email protected]> > *Subject:* Re: Stus-List 3GMF knocking sound > > > > Yea I did that today and started it up and it sounded fine. However I > didn't put it in gear or take it out of the slip. The racor was full and I > didn't see any water in it either. > > > > Now it does vibrate pretty good under operation. I looked at the engine > mounts though and none seemed to be cracked or anything. What should the > mounts look/feel like? How much vibration while running should it have? > > On Sat, May 26, 2018, 6:50 PM Josh Muckley via CnC-List < > [email protected]> wrote: > > Kevin, > > > > Fill the fuel tank with 6 to 10 gallons of fresh fuel, try it out, and get > back to us. Check your racor filter for air. Low fuel/air in the > line/water in the line can all cause rough operation. These Yanmars have a > lot of backlash in the engine and when you get rough operations the clutch > plate springs can bang. If you have a loose/broken/soft engine mount it > can allow the engine to bang around pretty good too. > > > > Josh Muckley > > S/V Sea Hawk > > 1989 C&C 37+ > > Solomons, MD > > > > > > On Sat, May 26, 2018, 2:30 PM Kevin Paxton via CnC-List < > [email protected]> wrote: > > Hey Everyone, > > > > Well we were lucky enough to be able to take out our 34 this past > Wednesday for the Blue Angels show in Annapolis. On our way back our Yanmar > 3GMF would occasionally make a knocking sound. I'm hoping you guys might > know what could have caused it. > > > > When it happened: > > * We were about to enter into the mouth of the Magothy and I was taking > down the main. My wife had the helm and yelled up saying that something > didn't sound right with the engine. She throttled down and when I got back > everything sounded ok. She said that it sounded like it was going to die. > Like it was running out of fuel. > > * We kept it running slowly for a bit without issue. Then I tried to speed > us up again. After about 5-10 mins it started making the noise again. To me > it sounded like a loud knocking or banging sound. I immediately reduced > power again and it immediately went away. > > > > Conditions: > > * At the time it started occurring we had about 1/8 of a tank of fuel. > > * Heavy, choppy waves for a large portion of our trip due to lots of power > boats. However, at the time it occurred, seas were calm. > > * At start up after we sailed for a bit the prop had trouble opening and I > had to reduce power a couple of times to get it to open. > > > > Observations: > > * I didn't see anything incorrect or worrysome during operation. > > * No leaking oil, fuel, or water. > > * Racor water separator doesn't show any water in the bowl. A little gunk > in the bottom but not much. > > * When power was reduced, everything sounded normal and operated normal. > > > > Thoughts/Questions: > > * Could low fuel/dirty fuel/water in fuel make this happen? > > * Could this be more of a vibration from the prop not opening properly? If > that's the case, could it be indicative of something in the strut or > cutlass bearing? We have in the past had A LOT of problems with the prop > not opening. > > * I did notice that during operation on the way back that occasionally the > undulation of the waves caused some stress. I'm assuming just because of > stresses on the prop. > > > > Today I filled up the tank and started it up in the slip. It started > immediately and didn't sound like anything was wrong. I brought the > throttle up and down and everything sounds absolutely fine. So I'm at a bit > of a loss as to what to check/do. I do know that I still need to change the > oil and I am planning on changing the fuel filters as well. > > > > I did notice that I am able to see the notch in the prop shaft where it > meets the gearbox. There does not seem to be anything on the shaft that > would indicate that it shifted at all though. Is this normal? > > > > Would love some help from some of the yanmar experts on here please. > > > > Kevin Paxton > > '82 34 #473 > > Japhys Spirit > > Cornfield Creek, Pasadena, MD > > _______________________________________________ > > 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 > >
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