Hello,

I ride a 1997 1200 sportster with 1400 big bore kit upgrade. Runs great except it is pushing oil back thru the crankcase breather when hot and is at it worst at highway speeds.
I've heard this could be due to a faulty seating of the oil pump check ball but I would then expect wet sumping to occur which does not.


This seems a common problem on earlier (pre 1980) models but unusual on the evos.

I'd appreciate any suggestions.

Chris