crankcase overflow

[trx53r]

i have a 2007 450er and i race motocross and ive been having issues after a race with a ton of oil ending up in my air box. its coming out of the crankcase breather tube but i dont know why. i have an athena 490 kit with the athena low comp. piston and a hotrods stroker crank and a stage three hot cams cam. has anyone had this problem or know how to fix it? the motor runs fine i just cheack the oil after every ride and make sure its at the right level and i do not over fill it because i have heard that could cause it.

[ghott]

Do you have the two vent lines separated so that you are sure it couldn't be coming from the valve cover vent?

I'd check for bad rings...or a cracked piston.

[trx53r]

i dont have them seperated but thats a good idea ill do that and check the piston and rings thanks alot for the help!