Thanks for the reponse. I held the spur gear, pushed the truck and the wheels did not move. I assume this is what should happen.On a side note, what is the function of the spring in front of the spur gear? I'm hesitant to hold the spur gear when the engine is running as well as during a rev up. Won't the clutch engage on rev-up and turn the spur gear? I don't want to lose a finger (I almost did on one of my planes).Idid remove the clutch bell and I think the shoes look fine. They don't look beat up. The springs are really tight and I was suprised on how much force is required to openthe shoes. With respect tp your related story, you reference a "stripped button". What isthis button you are referring to? I apologize forquestions regarding probably basic terms, however I am still learning the hobby. One more item. The exhaust coupler has a small hole in it, don't know how. Will this significant ly affect the engine performance or can I take my time to replace? Thanks again.