The 40LA is a less than desirable engine for that airplane and it would be a poor choice in your situation since using the known weaker (consideably weaker) engine will only compound the difficulty in flying the airplane.

The 46FX is on the other hand the ideal engine for the airplane and will make it somewhat easier to fly. If that engine is truely new and never run it is highly likely fine as well as the berings. It would be a big mistake to start a major stripping at this stage of the engine just on speculation from these forums.

Speculation is all any of us can offer, you need to have the engine inspected by an experianced modeler before you start tearing it down. This stripping the engine syndrome by new modelers who have acquired older stuff very often is totally uneccessary and often results in a screwed up engine as well as tremendous frustration. That is a great engine you got there. The very first step is as already stated in this thread is to stop turning it over dry. Get some fuel in it first through the carb and glow plug hold as well as the exhaust. In fact stop turning it over at all untill ready to start it beyond just confirming you got the #10 back where it should be.

That engine as well as most modern non ring two stroke engines has a taper bore with a subtancial choke. This engine has a piston fit that is free and loose fit at bottom dead center and a grinding to a halt crunch fit at the top dead center cold especially dry. This is what it is intended to do and what you are also feeling. Its Normal.


My apologies first off if it offends but someone needs to say it. There is very much more to prepping the airplane properly for flight than what you stated and if you refuse all on site help for Learning to operate your engine, Prepping the airplane for flight and flying your airplane, The flight will not last more than 30 seconds. I also suspect most of the responders in this thread would also agree as many of us who mentor new folks day in and day out, see this type of thing virtually every day at a busy field.

My appoligies

John