crank vibration

[sligers2ltr]

Help me please, the holes drilled in my 88 lt250r Suzuki crankshaft are they stock. Bike vibrated like crazy when I bought it, ripped the engine apart and found this. Dealer can't tell me anything.

[Kane]

First thing you should have looked at when disassembling was if the balancer was positioned correctly. Even one tooth off will cause vibration. Were the crank bearings bad? One or both? Was anything damaged? Other than vibration, how did it run, idle, perform?

[emmerth]

I think kane is on the right track with the balancer.

I would also replace the crank bearings since you are there.

[sligers2ltr]

Hey, thanks for reply, yes i have done everything obvious. I replaced every bearing, from the a-arms too the axle. The crank was sent to Quebec for rebuid. The balancer was lined up right. I checked as I was rippin it down.

[emmerth]

How did it run before you tore it down (with the exception of the vibration)?

[sblt500r]

that looks stock to me but i would have to check my extra parts to no for sure. do you know that there are 2 marks to line up? one on the balancer and one on the crank gear. if the one on the crank is off it would still vibrate even if the one on the balancer is lined up.

[Kane]

Actually 3 marks. One set lines the balancer gear to its shaft, one set lines the gear on the crank, one set lines the crank gear to the balancer gear. You should also check crank run-out. I found an LT500 crank that the clutch side was wobbling a full .030 out of spec. Made the machine feel like an exercise belt.