Engine down

[Weazman]

I just started into rc a few month ago but i know how to land and fly my trainer airplane but now i need some advise on my 40 size engine. I will get it started and lean the engine anough to take it off the glow starter but some times even at 75% throttle the engine will quit. I dont know why but when i get it into the air about three mistakes high the engine wont quit. and the engine has had about half a gallon ran through it.

[Dave Robelen]

Hi,
It sounds very much like the glow plug is too cool for the engine and fuel. Try this test. Crank up at low power and keep the booster on the plug. run the rpm's up to about a very fast idle and pull off the booster. If the rpm's drop significantly when you remove the booster, the plug is too cool. You did not mention the engine or fuel, but my best results are with a K&B idle bar plug. Try several different brands of plug until the revs stay the same when you pull the booster off the plug.
Regards, Dave

[belbourn]

had that problem at the beginning of this season.......turned out that i had a pin hole in a fuel line and that there was not enough pressure in the tank to push the fuel up at higher throttle positions so the engine wasnt getting the fuel that it needed