michael whiteman
Well-Known Member
- Local time
- 12:10 AM
- Joined
- Mar 2, 2021
- Messages
- 596
I have a 5:1 belt drive trans on my 4 stroke engine. The 6.25" cast aluminum driven pulley that has 100 teeth also has .050 lateral run out, or side to side wobble. Who knows why, maybe a bad casting or the 1/2" shaft hole was drilled at an angle? At about 2/3 throttle this will produce a vibration that remains to max RPM. The worst case scenario fix is to buy another trans and hope for a better pulley this time. There seems to be NO replacement parts for any of these transmissions. Does anyone have a junk trans that would sell me a replacement?
I was thinking maybe chuck it in a lath and machine the sides square. This would narrow the tooth width but I don't think it will be a big deal. After this I would attempt to balance the pulley by drilling lightening holes in the heavy area. I thought about heating the pulley with a torch while it was in the lath and trying to pull it back into shape but working with aluminum is pretty scary. It all goes to s**t in a hurry if you're not paying attention. Any other ideas more than welcomed. Thanks in advance. michael
I was thinking maybe chuck it in a lath and machine the sides square. This would narrow the tooth width but I don't think it will be a big deal. After this I would attempt to balance the pulley by drilling lightening holes in the heavy area. I thought about heating the pulley with a torch while it was in the lath and trying to pull it back into shape but working with aluminum is pretty scary. It all goes to s**t in a hurry if you're not paying attention. Any other ideas more than welcomed. Thanks in advance. michael