[SpudRider]

Originally Posted by pyoungbl

Ducati, Triumph, Moto Guzzi, BMW...all vent to the airbox....at least all of mine did. EPA won't pass them if they vent to the atmosphere. Note that all of them are much larger displacement engines so the pumping action is more pronounced. Good venting is critical because otherwise you risk blowing oil seals in the engine.

Thank you for posting the good information, Peter.

I assumed all bikes with EFI vent to the air box. All of my street legal bikes vent to the air box. Many dirt bikes vent to the atmosphere, but they don't need to pass EPA or DOT requirements. I am wondering if your previous EFI motorcycles employed an OCS, or if they vented directly to the air box without an OCS?