Hye i have a 85 350X and it smokes on start up and for about 5 min after. when it is warm it is fine. is this because of dried out rubber valve stem seals, like in a car??? or is it something else like rings?? the previous owner said it was recently rebuilt with a high compression piston. if it is the valve stem seals how hard are they to change out?? thanks for any help.

 

Loofer, it does sounds like bad valve stem seals. The cylinder head will have to be removed and disassembled.

 

Mine did the same thing. When you take the valve stem seals off check the stems for small hairline cracks's dont think that you can just cover them up with new seals it wont work. I replaced 2 of my valve guides because they where cracked everything was smooth from then on. I do reget the 12-1 wiseco because of the high octane that you have to run.