Help!!! I have an older model OS MAX 40 FP engine that has started to overheat. The engine has spent a number of years (multiple, but that is another story) in a box waiting for the completion of the trainer (Kadet Mk 2). The model was recently completed and the plane flew fine for approx. 10 times.

During the last 2 flight the engine ran fine (approx. 50% throttle) for 10 minutes and then started to miss as if it was running out of fuel. Upon landing I noticed that the engine was rather hot (fuel tank was approx. 50% full). Needle valve settings had not been changed.

Any suggestions on what may have changed that would make the motor overheat???