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76 CB750 Noise

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Halcyon402

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Hey guys. I am new to this forum and to working on motorcycles so I would appreciate all the help I can get. I purchased a cb760k6 and when trying to electric start the bike, it makes a loud clunking and rattling noise. I looked around other forums and they say it could be the starter clutch. Any suggestions of what it could be and how I could fix it will be helpful. Thanks.
 
Yes it is the starter clutch. Mine did the same thing but I put a new roller and spring kit in it.
 
It should fix it as long as the surface on the gear isn't worn to bad. If it just started to make the noise it should work. If it has done this for some time the rollers will wear slight chatter marks on the race of the gear and the inside of the alternator in which case it may or may not work right. That is the kit I used and it fixed mine. Let us know how it works out.
 
So I took the cover off and now I am having trouble taking the bolt that is attached to the rotor. Every time I a turn it, the rotor turns as well. Is there a special trick to keep the rotor from rotating? Also, I have been doing some research and read that I would also need a rotor puller after I get the bolt off. I was looking at the rotor puller itself and it just looks like a bolt. I know people hammer at it but I am confused at how hammering it will get the rotor off. hmm...
 
Put the bike in gear to keep the crankshaft from turning or use an air or electric impact to get the bolt off. And just to make sure....is just the rotor turning or the rotor AND the crankshaft? The rotor is a taper fit to the crankshaft, that tight fit is the only thing that keeps the rotor from spinning on the crankshaft. The puller is like a bolt but is a harder material. Once you get the rotor bolt off you will see that the inside of the rotor is threaded. The rotor puller is threaded into the rotor and tightened against the end of the crankshaft. When you tighten the puller it will force the rotor off of the taper of the crankshaft. Dont hammer on the end as you can damage the crankshaft and/or the thrust surface in the case.
 
Alllllrighty !!! I just got the generator rotor removed. Now how do I install the new rollers, springs and guide pins?
 
Pull the starter gear out of the rotor and you can pop the rollers out and you can then pull the spring and guide out. Do one at a time. It is pretty self explanatory once you take the first roller and spring out. A pick and or a thin screwdriver will make it easier to push the spring and guide around in the rotor while you get them into position.
 
Hey guys. So I replaced the rollers springs and guides in, put new gaskets and bolts on and filled it with new oil and tried to fire it up last night. When I hit the electric start, it starts to turn over but the loud clicking noise occurs again but not as treacherous as before. Kick starting it doesn't make the noise but it doesn't seem to turn over as well as an electric start. I'm out of options. Should I record a quick video so u know what I'm talking about? Btw, thanks for all the help so far. You guys are great.
 
More than likely the surface on the big stater gear that the rollers run on is worn too much. The roller kit is a cheap "1st try" thing with the starter clutch, but the race on the gear does get worn and especially if the slipping and noise has been going on for a while. The only fix for that is a different gear , unfortunately it has been discontinued by Honda. If you can find another used one to try or maybe get lucky that some shop has one stuck away somewhere. The kickstart and electric start are not interconnected that is why there is no noise with the kickstart. On a side note. I did have this problem continue once after I replaced the rollers. In that motor I was running a synthetic motorcycle oil, as a last ditch effort I drained the synthetic and put traditional oil in and after a couple of starts the problem went away. I am guessing the race on the gear was marginally worn and the traditional motor oil gave it just enough friction for the rollers to catch and make it all work.
 
The sohc starter is not gear reduction inside, only gear reduction is the gears under the alt. cover.
 
No I am talking about the big gear that goes into the rotor. That big gear has a smooth surface that the rollers ride on.
 
The slipping stater clutch is a problem that does show up once in a while. Normally on really high mileage or lack of oil change type of motors. There actually was a Honda service bulletin when the 750 first came out and had problems with the rotor spinning on the crankshaft because of the bolt loosing tension causing a similar symptom. But it is an obvious problem when you pull the cover and the rotor is loose on the crank. Honda bulletin also stated using a new rotor bolt each time the bolt is removed because if you look very close the newer bolts had a hole drilled in the threads and there was a plastic plug put in that acted like lock tight.
 

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