440 ex o-ring...help???

[chad400]

just put a 89mm kit in my bike,completed it but did not start motor yet. i noticed that there was no o-ring in the gasket kit for the base of cylinder,should there have been one, or is that only on the stock cylinder....please help ASAP!!!!! nervous about starting motor THANKS CHAD:confused:

[YZ400EX]

You will be fine without it..

[cals400ex]

yep, i don't run one either. when i was in the same situation i asked mickey dunlap and he said don't use one.

[BLEEDRED]

mickey dunlap

Enough said!!

I did put one on my 440 last spring and when I tore it down this winter it was cracked and hanging on the bottom of the cylinder. Too much heat!!!! I won't be putting one back on...