I'm mounting an OS 4 stroke inverted. Do I need to run it on pressure. This is my first experience with 4 strokes.

Jack:

Just make sure the tank is relatively centered on the spray bar. Carb adjustment when inverted can be a little harder than on the side or upright, but when dialedin there's no real difference between a 2s and 4s engine. If you can set up the 2s engine you can do the 4s.

Bill.

Often on the OS four strokes, the engine has a surging problem. Try adjusting it out with the needle valve, if this doesn't work, sometimes, you can disconnect the muffler pressure line and get away from this surging?

Enjoy,

Jim

Thanks for your help guys