I have a somewhat dumb question: when I rotate the engine by hand (by rotating the gear on the crankshaft on the side near the clutch), the engine turns freely, except when the cylinder begins to seal near the top of its travel, and also when it breaks the seal on the other side of the rotation. Is this simply resistance from making and breaking the seal on the cylinder and the combustion chamber, or is something in the way of the cylinder that needs to be fixed?
Maybe I didn’t understand your post. Are you turning the gear on the clutch? Resistance on the compression stroke as the piston reaches the top of the cylinder would be normal. However, turning the clutch drum gear should not cause the crankshaft to turn.
LAD Specialties customer / tony kart / rotax / kt100