hi everyone

i recently finished rebuilding a 91 sporty chop w/ a 1200 wiseco kit. only has 6300 miles on it and about 100 with the new top end.

i had the bike running well then i stopped at a stop light and all of a sudden heard a very loud grinding type sound. actually sounds like a mix of ball bearings rattling aroundcombined withthe sound of electricity arcing to a ground. it is loud enough to be heard over the short drag pipes.

so i checked the rotor and stator. they were actually fine but i was reading my multimeter wrong!! and put new ones in. i had to go into the primary anyway to make sure there was no debris or anything. it was pretty clean but i cleaned the whole thing thoroughly, put new fluid and a new gasket and new stator/rotor. fired up the bike and still get the same sound. i didnt pull the tranny.

the sound follows the rpm's of the engine. more rpm = louder, less rpm = softer. when i turn the bike off the sound goes away but after an extra split second (like if you put rocks in a can and shake the can, the rocks spin for a sec after you stop shaking the can).

tranny shifts solid and fine thru all 5 gears and back. no probs going from any gear to any other gear. i adjusted the shift pawl, new clutch cable. bike still runs fine, tho it was bucking a bit.

brought it to a local dealer who listened and said he thought it either primary chain or maybe a bearing going. the primary chain is tight per manual specs tho i just realized that i never adjusted it at the tight spot - just adjusted it wherever it was. could this be the issue.

could this be a bearing issue and if so, which bearing? can i do this repair at home? or could it be something with the primary chain? i am relatively competent as a wrench but am also smart enough to know that some things are beyond my capabilities. is replacing a mainshaft bearing - if this is in fact the problem - something the home mech can do? if it is a tranny issue i have rebuilt those so i feel i could do that.

i am really wanting to ride this to laconia on sat - so i am anxious for some help.

thank you all

 

One thing you can do is remove the primary chain but keep the rotor on and run the engine......you can do this with the primary cover off, but make sure you wipe the oil off the rotor and stator so you don't get oil flying everywhere. This way you can easily tell if it's from the engine. IF all sounds normal, then it's gotta be in the tranny. Clutch bearing would be the first thing I'd take a good look at, i've seen these go a number of times. We had to preplace my buddies clutch bearing not too long ago, the thin metal thing that spaces out the ball bearings tore apart, the ball bearings stayed in the races though so the bike still was ridable but made the same sounds that you described. We put the new bearing in, pretty easy job.

 

thanks Drum!

that is useful to me as I was not sure I should run the engine w/ the primary off.

So if the sound goes away once the cover is off then I would suspect that the chain is hitting the case?

Could you describe the difficulty in replacing that bearing? also, would that bad clutch bearing cause the bike to lunge/surge from time to time?

 

I just recently noticed the same exact problem on mine and was about to ask the same question today. This helps out alot. I will pull the primary off thursday or friday and let you know what I found to be the problem. I did the same thing you did, checked the chain and fluids and all good. I was thinking of clutch issues so the bearing may be the culprit.

 

Well you don't want to run it too long with the primary off, basicaly just start the engine, and stop it after like 15 seconds, and like I said make sure the primary chain is NOT on, but the rotor is on. Also like I said oil will fly off the rotor if you don't wipe it down good. It's basically a simple method to isolate the engine from the tranny noise.

The clutch bearing is pretty simple, you do have to pull the tranny out though. I don't remember all that was involved with taking the trap door assembly off, so follow the HD manual. But anyways, once the trap door was out, thers a simple retaining ring that secures the bearings in, so take that out, then using a socket about the diameter of the bearing, gently tap the bearing out of the trap-door. Then do the reverse, tap the new bearing in till it seats, put the retaining ring on, and put the tranny back in. If you have access to a small manual lever shop press, it would be better to press the bearing out and back in. If you tap it in, you have to be real carefull it doesn't **** over while it goes in.

But don't assume this is the problem, make sure you check and inspect all bearings, and gears, cause it may be something else causing the noise. I think you already learned your lesson after buying the new rotor and stator, so make sure you are positive something is broken before you buy a new one.

By the way, about the possibility of the chain hitting the case, if you look at the inside of the case you'll see scratch marks if it was hitting.

 

Occasionally I will hear a grinding sound on my 06 sporty custom 1200 while I am cornering on a curve or going around a corner. This has happen 3 times that I am aware of. Last week-end while on a 160 mile ride it happened twice. It sounds like the kick stand is dragging the pavement could be primary.
Any ideas????
Thanks for your help.

 

Use thicker oil hahahahaha sucker!