I have just bought an OS 70 Ultimate engine and mounted it in a 40 size Sukhoi. I'm running the engine on 15% nitro and 15% synthetic oil. The engine is extremely easy to start an idles well but I have a big problem with the throttle response. If I run the engine for more than 10 seconds on full speed the engine will stop almost immediately when I try to throttle it back to idle. I have adjusted the full speed needle to about 1.5 turns and I have also tried almost every setting possible on the idle screw. The engine has been run about 2.5 litres of fuel but there is no sign of it getting better. The tank pressure seems to be fine and the fuel plumbing looks fine.

I have flown the plane 2 times with this engine and both flights ended up with a dead stick landing.

Has anyone had a similar experience with this engine?

I'm getting real frustrated about this so any help in this matter would be very much appreciated.

Happy flying
Sondre