Hi Ian,

I tend to disagree with the two comments above. A 24x10 prop is well within the stated specs for your engine. In fact, the 24x10 is almost in the middle of the recommended props for this engine.

It sounds to me like your engine is set very rich. The MVVS manual gives some recommendations on settings, of L=1.45min and H=1.10
Try the following:
1. Set both needles to the starting point above
2. Lean out the H needle till you get maximum RPM and then richen it by around 1/8th of a turn
3. Set the engine for high-idle. Now lean out the L needle for max RPM
4. Repeat 2 and 3

I know this is not quite the procedure in the MVVS manual but it will get you to the same point