Hi, I have an Lanier Explorer 40 trainer with a new just run in SC 46 glow engine driving an 11x6 prop.(SC are Chinese engines available in New Zealand, club guys here have been having a good run from them) The engine starts very easily and the plane flies very well. My instructor is very impressed. However when moving the throttle from half power (a setting the planes flies very well at) to full power, or from idle to full power the engine will just stop. The engine tuning appears correct, flying around very happily on half to full throttle the engine just purrs, making all the right sounds

We have tried different needle valve settings, but with no success, different brand of fuel, current using brand new Sig Championship 2 stroke glow fuel, 10% nitro. The previous fuel was club mix and had no nitro, removed and checked the fuel tank and lines in case a line had moved and was causing foaming in the tank and hence fuel starvation, everything fine and no change to the engine behaviour. Tried 3 different glow plugs, and A3 which came with the engine, a Tower plug(don't know much about that one heat range and so on) and a genuine OS#8. The tank and carb have been checked for air leaks, but all is fine. Shortened the fuel line so it was not waving in the air stream and may be getting excessively cold.

It is summer here so the air temp is warm in the mid to high 20degree range(today is 26 -30 degrees) so I don't think believe air temp is a problem. The tank and set up is a as supplied by Lanier and looks very ordinary and normal. My very experienced instructor can not find any fault or problem here.

Running out of ideas of where to go next to solve the problem. Wondering if the glow plug may be getting cooled by the incoming fuel and air when the throttle is opened and no glow = no go. However I believe that the OS#8 is a hot plug. I believe idle bars were added to some plugs but I can't locate any glow plugs with an idle bar, are these a thing of the past, would it helpanyway?

My instructor says I am ready to land, but is not letting me until this engine problem is corrected as if I mess up the landing I can't put on some power and go round again, as the engine will stop.

Thanks for any suggestions, I a have an older OS 46 engine and are just about ready to put this in the plane!!

Cheers

David