I have a stock 01 CR250 and have a problem with a large amount of oil coming out of the exhaust. I took the bike part and found the problem. Oil is flowing up past the pinion shaft and drive shaft of the exhaust value system and straight into the exhaust. I wanted to know if anyone have any ideas on how to fix this problem. I cleaned and greased everything, should I try running thicker oil (currently 10w-40). Should I use Honda HP transmission oil instead of engine oil? Should I replace the pinion shaft and if so any ideas on where I could pick on up? Thanks for the help.
