everspeed

I clicked on Hyper701's link. But let me warn you, I wouldn't go too far with the head shim thing. Head shims are added or removed to enhance the engine's ignition timing, according to the fuel and glow plug type you're using. These engines use compression and heat to start combustion. The more compression and heat that's present, the higher the timing will be advanced. The lower the combustion/heat, the lower, or more retarded it will be. Too far advacned and you get pre-ignition, and even a loss of power. Cause the fuel is combusting too quickly, and thus slowing the piston down before it gets to TDC. Too far retarded, and the fuel will not be burnt complete enough before it leaves through the exhaust port, and there won't be enough pressure while at TDC. You can ask alot of Force .26 owners about thir engines overheating, and not making much power. Most of the time, I'll get these people to add a few head shims, and the problem is cured.