I have an SC 25 engine and the engine does not cut out when I close the throttle on the carb compleatly. It is a brand new engine the carb stop has been moved so the carb now closes compleatly. No matter what I do with the engine it will not stop or cut from the transmitter. It will just idle very slowly I don't know where the engine is getting air from and it is anoying because the engine will keep running.

Andrew

Make sure the carb is completely seated in the engine and the O ring compressed. If it will not shut down remove the carb barrel
put a little petroleum jelly on it and put back if any air leaking around the barrel this will stop it. of course it will wash out with the
fuel but will last long enough to check it out and make sure you cannot see any opening at all when throttle pulled back (sounds like you have)
martin

I have made sure that the O ring is compressed and the throttle is fully closed, there is no opening when throttle is fully closed. I have tryed the petroleum jelly. and the engine still keeps on running, could the engine get air from the crank case because I have now found out that the engine will stop when it is cold and not warmed up properally. When the engine is warmed up and running after the flight the engine will stop after a little bit of time. My other idea is that because the engine is an ABC could it be that the piston when the engine is warmed up does not seal properally and lets some air through.

Andrew