Hey Propbuster, the picture in your avatar IS the Xtra Easy I am talking about. Great trainer. The MDS 40 is a great engine too. Once you get it tuned up you don't need to touch the needle. Start by adjusting the low spped needle and get it to where the engine dies with a slight increase in revs when you pinch the fuel line. Then work on the high speed needle. If the engine is new (and I bet you it is if it was only flown 3 times) run it rich for a while. Something I did, because I was flying in a grass field is made a filter for the carb intake, so that grass and seeds would not get into the engine. I used the end of a plastic 5 cc disposable syringe and epoxied a fine metal mesh from a faucet reapir kit (from the aereator)
Luis