Hi All,


I finally got my converted Ryobi 31cc running again. I did most of the possible hop-ups from Wacker engines including:

Pitts low restriction muffler
Large bore carb
Shaved and balanced flywheel

The first time I started it, it turned a 16-8 over 8K but it was spitting gas all over the place from the carb and the hi/low needles didn't affect anything. Wacker sent me a different carb at no cost and I just recently (yesterday) got it running. It sounds great and no longer is spitting gas all over, but it only runs in a very narrow area of butterfly position. If I move the butterfly/throttle much past 1/4, it slowly dies.

Can somebody explain a good process to systematically fine tune the lo/hi needle adjustments to get max performance from this engine?

Thanks, Jim Walker

Ok try this ,turn your low end in all the way carefull not to tighten. Back it out 3 turns do the same with the high end. This should make it slopy rich, Start your engine and at full throttle start turning you low end in till transition is good. Turn your high end in till you get a tach number which will depend on the size prop. If you are using a 18-8 you should get about 6,700to 7,200 depending on the mods. The idea is to not hear any sounds of the engine straving or getting too much fuel. To me it sounds like you are way too lean on both needles or have a vaccum leak form your carb gasket, also make sure your crank pulse is getting to the carb. Good luck