Yeah, man, old soup in an old pot. Let me add my last two cents coin. I went along my analysis of the problem and found the original engineering flaw. If you look at the father of the alternator of the CBX 650, i.e. the alternator of the CB 750, you find the evolution path. They wanted to integrate in the center of the stator and rotor the excitation winding. To do this, they had to place a metal support right in the middle plane of the alternator. Due to the impossibility for the magnetic poles to cross this median plane, the six north poles send their magnetic flux in one half of the stator. The six south poles, on the other side, receive teir flux from the other axial half of the stator. Unfortunately, the engineer who designed this solution forgot that stators are made of stacked flat iron plates. Beetween these plates, there is a thin varnish coating which prevents induced currents to flow inside the stator iron and make losses. And these coatings, also create gaps for the magnetif flux. The resistance that this magnetic flux must counter to get from one half to the other half (axially speaking) of the rotor creates a difficulty and a bad power factor for this type of alternator. In order to get some charging of the battery, the current was set higher in the excitation winding in the middle. It is now very near of the burning limit. So, when you ride the bike for a while in town, on summer, and worst with the headlamp lit, this excitation widing burns. It could be what happened to this bike, like to dozens of them each year.
I'm exploring two solutions 1 - To rewire the excitation winding with a thiner gauge wire, which will lower the power loss in it and allow lower temperatures in the center of the winding. Of course, the bike will not charge under 2000 rmp. But it's already better than "burn once a year and doesn't charge at all one burnt". 2 - To redesign the rotor with permanent magnets and longer poles (taking all the width of the stator). Will need to change the rectifier / regulator to one designed for three phased permanent magnets alternators. I will tell you later what solution I can try. At 19:15 17/12/2008 -0600, you wrote: >Oh man, that discussion is almost as much fun as the "which oil is best" >discussion. It's all in the archives, short answer is they don't charge >unless you keep the RPMs above 2.5-3K. The long answer involves >differences of opinions and electrical theories that were mostly over my >head ;) > >-Kyle > >On Wed, Dec 17, 2008 at 7:07 PM, Andrew ><<mailto:[email protected]>[email protected]> wrote: >> >>I took a few pretty nice rides today and it was riding good. I am >>noticing that the charging system doesn't really charge the battery >>well. >>After a few times riding it , the battery is dead. >> >>Do these have alternators like a car? >> >>On Dec 17, 7:51 am, Andrew >><<mailto:[email protected]>[email protected]> wrote: >> > Ok, I'll try turning them down. What would I expect to see if they >> > were not metering anything. How would the bike react? >> > >> > A friend of mine gave me this bike so I know he has rebuilt these >> > carbs before. Thats probably when the one screw was replaced with a >> > different one and I know that's why most of the rubber in the carb is >> > in good shape. >> > >> > Thanks, >> > Andrew >> > >> > On Dec 17, 12:33 am, Dennis Hammerl >> <<mailto:[email protected]>[email protected]> wrote: >> > >> > >> > >> > > 2 5/8 sounds a little "much" to me. At that setting they wouldn't be >> metering anything, just open. Try 1 1/2 to start. I really don't know >> the exact setting, I always count the turns in to seat before I remove >> them. put 'em back the same way. It might be in the Honda shop manual. >> For as much as I'm a "by the book" person, results count more. Glad you >> got it up and running. Learn anything ? Always better when you do. >> > > The odd mixture screw is from an older bike. If you broke off the >> caps (too easy to do) you would be left with a skinny post. As long as >> it has the same profile as the others. When I see stuff like that, a red >> flag goes up and I examine each part for more mods. Somebody else has >> been here before and I don't know what they where up to or how good they >> were. >> > >> > > --- On Tue, 12/16/08, Andrew >> <<mailto:[email protected]>[email protected]> wrote: >> > > From: Andrew <<mailto:[email protected]>[email protected]> >> > > Subject: [Nighthawk Lovers] Re: Starting problems >> > > To: "Nighthawk Motorcycle Lovers!" >> <<mailto:[email protected]>[email protected]> >> > > Date: Tuesday, December 16, 2008, 9:02 AM >> > >> > > I got it running last night. I took everything out again, used some >> > > copper wire to clean out the jets and put it all back together. Fired >> > > up after a little starting fluid and now starts everytime. I read >> > > that 2 5/8 turns from bottomed out are the factory settings? When I >> > > first started it, I was getting a littel white smoke coming out the >> > > pipes. Is it running rich or just need to warm up? >> > >> > > I wondered why the bottom screw in the picture didn't have a >> > > "nob". >> > > Thanks for all of your help. >> > >> > > On Dec 15, 11:55 pm, Dennis Hammerl >> <<mailto:[email protected]>[email protected]> wrote:> Yes they are. >> Looks like one isn't original (nearest) and the stops >> > >> > > have been boogered on a couple of others. Great that you can remove >> and clean >> > > the passageways. It / they control idle mixture and up a bit past >> 1000RPM. If >> > > you spray into the hole it should discharge from three holes in the bore >> > > (throttle plate end). Each one is exposed at a different throttle >> opening. spray >> > > carb cleaner into the small openings in the bore (air cleaner side, >> one on each >> > > side) and look for liquid coming from the hole the slow speed jet >> was in and the >> > > the hole the mixture screw was in. Air enters where you sprayed into >> and picks >> > > up fuel at the jet tower where the slowspeed jet was and continues >> through to >> > > the bore.> Now, lets see the inside of the chambers. Remove the >> bowls and internals. >> > >> > > One at a time please. Did you locate the wire sizes I posted ? >> > >> > > > --- On Mon, 12/15/08, Andrew >> <<mailto:[email protected]>[email protected]> wrote: >> > > > From: Andrew <<mailto:[email protected]>[email protected]> >> > > > Subject: [Nighthawk Lovers] Re: Starting problems >> > > > To: "Nighthawk Motorcycle Lovers!" >> > >> > > >> <<mailto:[email protected]>[email protected]> >> > >> > > > Date: Monday, December 15, 2008, 7:57 AM >> > >> > > > Can you take a look at this picture and tell me if these are the idle >> > > > mixture screws? These are what I took off and they didn't break. >> > > In >> > > > fact, they came off very easy. They were a little gunky so I am >> > > > soaking them and recleaning everything again. I'd like to make sure >> > > I >> > > > get everything this time. >> > >> > > > This link has the picture. >> > >> > > ><http://home.comcast.net/%7Ehbrown159/carbquestions1.jpg>http://home >> .comcast.net/~hbrown159/carbquestions1.jpg >> > >> > > > Thanks, >> > > > Andrew >> > >> > > > On Dec 14, 4:19 pm, Dennis Hammerl >> <<mailto:[email protected]>[email protected]> wrote:> >> > >> > > However you get them off, whatever works for you, etc. I remove the >> clamps >> > >> > > > from the spigots and stick a thin screwdriver under the rubber. Spray >> > > silicone >> > > > in and remove screwdriver. Pry bar is fine. I do remove all airbox >> > > mounting >> > > > bolts and pull back to give room. >> > >> > > > > Andrew; don't attempt to remove the limiter caps. Grind the >> > > protruding >> > >> > > > stops off. Then they can be removed without breakage. The stops >> only allow >> > > 270 >> > > > of movement, no stops gets you 360. Careful work with a mototool >> will do >> > > it in >> > > > minutes. >> > >> > > > > --- On Sun, 12/14/08, Kyle Munz >> <<mailto:[email protected]>[email protected]> wrote: >> > > > > From: Kyle Munz <<mailto:[email protected]>[email protected]> >> > > > > Subject: [Nighthawk Lovers] Re: Starting problems >> > > > > To: >> <mailto:[email protected]>[email protected] >> > > > > Date: Sunday, December 14, 2008, 1:11 PM >> > >> > > > > Actually I'd like to know the secret to getting the carbs out of >> > > the >> > >> > > > intake manifolds. I've actually been using a modified allen wrench to >> > > remove >> > > > the manifolds from the engine and leaving them attached to the carbs. >> > >> > > > > -Kyle >> > >> > > > > On Sun, Dec 14, 2008 at 12:04 PM, Andrew >> > >> > > <<mailto:[email protected]>[email protected]> >> > >> > > > wrote: >> > >> > > > > Hi Dennis and Kyle, thanks for the help. I am about to go out and >> > > try >> > >> > > > > your suggestions. The only part I have not gone through and blown/ >> > >> > > > > cleaned out are those low speed channels you talked about. I >> > > didn't >> > >> > > > > know you could (should) remove them. I'm hoping I can do it >> > > without >> > >> > > > > breaking them. I have cleaned out those jets in the bowls at least >> > > 4 >> > >> > > > > times. I used a couple of small pieces of copper wire that I >> > >> > > > > stripped. Must not have done a good enough job since it wasn't >> > > the >> > >> > > > > correct size. >> > >> > > > > Is there a recommended way to remove the carbs from the rubber >> > >> > > > > mounting holes? I use a 4 foot long pry bar to gently push them >> > > out >> > >> > > > > and back in after I loosen the clamps. >> > >> > > > > Maybe I'll take some pictures. Thanks Again, >> > >> > > > > Andrew >> > >> > > > > On Dec 14, 1:14 am, Dennis Hammerl >> <<mailto:[email protected]>[email protected]> wrote: >> > >> > > > > > YOU have a lot of work ahead. First off, if the carbs were >> > > really >> > >> > > > clean you wouldn't be writing about this. On the plus side, you >> > > don't >> > > > seem to be adverse to the labor required. Remove the carb assembly >> once >> > > again. >> > > > Do not separate from the "runner" that keeps them together. >> > > Remove >> > > > float bowls and jets. The slow speed jets are most likely blocked. >> > > Whatever rust >> > > > migrated through the system will be everywhere. Slowly clean all >> passages >> > > and >> > > > jets that fuel flows through. You'll need cleaning wires, pressurized >> > > carb >> > > > cleaner and compressed air. The idle mixture adjustment screws are the >> > > ones that >> > > > have the caps on them. They should be removed and blown out given the >> > > nature of >> > > > your problem (rust injestion) It is possible to remove the caps >> but most >> > > often >> > > > they will break off and leave you with an additional problem. I >> carefully >> > > grind >> > > > the stop tabs off with a Dremel. Gaining access to the fuel >> circuit they >> > > control >> > > > will allow you clean a vital area. When replacing> > the idle mix >> > >> > > screws, gently bottom out and back off about one turn >> > >> > > > as a starting point. The tabs prevented adjustment that would >> result in a >> > > rich >> > > > mixture and not comply with EPA. I recently posted the wire sizes >> required >> > > to >> > > > clean the jets of a 650 (#37 & #115). In the case of a rust problem >> > > like >> > > > yours, I route the fuel line to allow me to use an automotive fuel >> filter. >> > > Find >> > > > a place for it. My choice of carb cleaner is Berkbile 2+2 (not sold >> > > everywhere >> > > > due to hazard) When working on carbs follow the instructions of med >> > > school; >> > > > First do no harm. I might add that you need to verify that the >> fuel flow >> > > from >> > > > the tank is adequate. I open the vacuum with a syringe and blow >> back into >> > > the >> > > > tank. Rust is among the worst nightmares to deal with. Repeated >> cleaning >> > > is not >> > > > unknown. Always work on one carb at a time and do not switch >> slides. In >> > > fact I >> > > > don't remove them unless I suspect a defective diagphram. Before >> > > installing >> > > > carbs, support them in an upright >> > >> > > > > position >> > >> > > > > > and supply with fuel from an external tank source. Better to >> > > see if >> > >> > > > you have a leak now and not remove again. Observe the spray from the >> > > accelerator >> > > > pump and insure it works. Good luck. >> > >> > > > > > --- On Sat, 12/13/08, Andrew >> <<mailto:[email protected]>[email protected]> >> > > wrote: >> > > > > > From: Andrew <<mailto:[email protected]>[email protected]> >> > > > > > Subject: [Nighthawk Lovers] Starting problems >> > > > > > To: "Nighthawk Motorcycle Lovers!" >> > >> > > > >> <<mailto:[email protected]>[email protected]> >> > >> > > > > > Date: Saturday, December 13, 2008, 6:17 PM >> > >> > > > > > Hi I have an 83 Nighthawk and I am having a problem getting it >> > > > > > started. >> > >> > > > > > Before I start describing the problem I thought I should mention >> > > that >> > > > > > it sat for 4 years without being run. >> > > > > > So when I got it, I took the tank to a local shop and had it >> > > acid >> > > > > > etched and coated. I also took the carbs off, cleaned them out >> > > and >> > > > > > put it all back together. It ran great for a week, then I let >> > > sit. >> > > > > > The next tiime I went to start it, I realized the petcock was >> > > clogged >> > > > > > and the shop missed a spot on the tank. I took it back and had >> > > it >> > > > > > recoated. >> > >> > > > > > I took the carbs back of, cleaned them real good and put a new >> > > fuel >> > > > > > filter on. Now I just can't seem to get it started. >> > >> > > > > > When I go to start it, I twist the throttle a couple of times, >> > > set >> > > > the >> > > > > > choke and crank. It fires for a second or two, then dies. >> > > Never >> > > > > > staying running. I can never give it any "throttle" >> > > to >> > > > keep it >> > > > > > running. >> > >> > > > > > A couple of things I was wondering: >> > > > > > 1. Should I be tightening the either the small jets or the >> > > needle >> > > > > > valves from the air diagphrams above hand tight with a >> > > screwdriver? >> > > > > > Or should I leave them a >> > >> > ... >> > >> > read more ยป- Hide quoted text - >> > >> > - Show quoted text - > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en -~----------~----~----~----~------~----~------~--~---
