My son's 99 XC500 blows back oil into the air box. Enough that after a 75 mile ride, oil [a couple of spoons ] leaks onto the floor.
The reeds apear OK, no leaks from the oil lines, everything else is dry. Would appreciate some help or ideas.
No machine does not smoke excessively.
Other info. that may help-- pistons look OK from intake,exhaust,& spark plug holes. Compression is 121psi both cylinders.
Work done approx. 1000 miles ago-- Rebored .020 " over with new Wisco pistons,& Boison reeds.
Hope this will help!