I HAVE AN 08 APEX MTX WITH A STAGE 1 MPI SUPERCHARGER AND I KEEP ON BLOWING OUT THE PLUGS ON THE SIDES OF THE VALVE COVER GASKETS. I HAVE INCREASED THE SIZE OF THE CRANKCASE BREATHER AS THE HOSE WAS COLLAPSING. i HAVE SILICONED THE PLUGS IN AND THEY SEEM TO BE HOLDING BUT ONCE IN A WHILE IT WILL SPIT OIL OUT THE BREATHER AND IT VENTS HEAVILY PRETTY MUCH ALL THE TIME. I AM RUNNING ABOUT 10PSI BOOST. I RIDE WITH A GUY THAT HAS THE EXACT SAME SETUP AND HE IS HAVING THE EXACT SAME PROBLEMS. ANY ADVICE WOULD BE APPRECIATED AS I HAVE TAKEN INTO A DEALER AND THEIR "FIX" DIDN'T WORK.

If you're blowing out that gasket you have poor ring seal. Get the sled to a Yamaha dealer and get a leak down test done. I will bet you have hurt the block or a piston.