i have the .40 engine and i replaced the 3 bladed prop with a 10-7 ...i was wondering if the thick spacer that goes with the orginal setup is still needed with the new prop that i'm using...i have the Alfa trainer

The thick spacer is actually a flywheel. Technically, you don't need it., but it does serve a purpose. It makes the engine idle smoother, and setting the idle on any glow engine is probably the most difficult thing to do in the hobby. So, if you are prepared to figure out how to tune the idle setting of your engine, then remove it. The up-side will be that the plane will go from idle to full throttle a lot quicker, and your plane will be lighter. You must remember to re-balance the plane after removing the flywheel because otherwise you will end up being tail heavy, and have an unstable plane.

gus

ok thats what i heard but i just wanted to get another opinion.

thanx