hi Andrew, my 28 short frame did the same thing, and I've also made a plate to be able to ride in the meantime of fixing it. some previous owners would have tightened the generator belt way too tight to a point where they ovalized the hole in the casing and grooved the shaft badly. so i welded a plate on a thick square tube, put it in the lathe, faced it and bolted the casing onto it. bear in mind that the oval hole would actually be ok on the bottom of the casing because the belt would have pulled upward, therefore not damaging the bottom part of the casing. the most important part of the job is to center the casing in the lathe according to the pulley shaft when in proper position. i then oversized the hole in the casing until that hole was round and no longer oval. then i plugged the oiling hole on the top inside the casing and drilled another one on the bottom. i then machined the shaft until the grooves were gone, made a brass bush to fit, soldered that to the shaft and machined it to fit in the casing. i then made a spiral groove on the bush so that oil would be expelled back toward the inside. my generator spins counterclockwise. if you kick the kicker, that will tell the story. hope my rambling was not too painfull! those photos attached should help a bit. cheers. Daniel    

I would aim for around 0.0015 " clearance for oil. You could probably get a way with 1 thou. Make sure the bushings are running true in line. Carl-Erik has a post  here somewhere about the variations in oil drillings, there should be one to drain into the shaft from above, and one to drain back into case. Some also have a spiral in the shaft to feed oil back.

Make sure your engine breather is working fine, and also the small air bleed hole at the top of the trans tower is clear to vent.

Make sure there is no excessive end float in the clutch basket drive gear ( ie the end float on the trans mainshaft is not too excessive).

Don't run the belt too tight.

I have recently removed an aftermarket DU7 shaped alternator from a friends bike. It had way too much pull on it. It was stiffer to turn by hand thru the magnets than the alternator on my 350 V8 Chevrolet. Had ripped the bushing to pieces in several hundred miles. It did not produce a decent charge anyway, maybe it just needed to rev faster.

I know of several bikes running small lawn tractor or bay suv alternators that have way less pull and have caused no such issues over several thousand miles, altho they have more resistance than a traditional three brush generator.

Hope some of this helps, let us know how you go.

Tim

Good to hear from you Gene. Perhaps we could put a link to your site on our main web page ??

Tim

Thanks to everyone that replyed. I am going to work on the generator and test it shortly. Your information will be very helpful.

Best regards

,

Andrew Newstead