I've bought my first four stroke engines, after having flown helicopters with two strokes almost exclusively. I'm not entirely sure how to tune them, or break them in. I'm familiar with ringed engines, and bought a TT 54, and a Magnum 61 for my first four stroke victims. I'd like to run coolpower 15% heli, or perhaps powermaster 15% (the castor alternative).

How do you tune a four stroke? With a tach, but where do I start. The TT 54 will not hold anything above 3/4 throttle very long, regardless of needle setting. The valves are adjusted correctly. How do I tune the low end needle? Can you do the pinch test like a two stroke? Your help is appreciated.