will a os 91 four stroke no pump , run with the carb pointing down; engine mounted on a 45 degree angle?
thanks
curly

I have mine mounted inverted and it works fine. I believe that you can mount it in any position.

Curly,

You can mount your engine in virtually any position from upright to inverted, and it should run well. As you go from side-mounted to inverted, though, idle and acceleration could become problematic with any engine as the glowplug becomes more of a sump for liquid fuel at low throttle settings. That's common with any model engine.