Ways to track down an air leak
I have a relatively new Sirio .12 SG engine that I am having fits getting to idle much less tuned correctly
I am pretty sure I have an air leak or fuel leak somewhere in the Carb. The reason I say the carb is if I put another Carb on it, the engine acts so much better.
Symptons:
When it gets started, it is so rich you can hardly keep it running wihtout blipping the throttle. When it gets up to temperature, and say you go full throttle for a fews seconds (2-3), as you let off, the engine is still revvingvery high. Almost anything you do to the needle settings doesn't change the temp at all. Also, you can screw the low needle in all the way and the mid needle in all the way and the thing still runs and feels very rich at the bottom end. I didn't even think an engine could run that way. Another sympton is once I stop the engine (put hitting the fly wheel), after about 30 seconds or so, I see air bubbles in the fuel line. It seem to not want to keep the fuel pressure.
Suggestions:
I need some suggestions to determine how to find the problem. I had already sent the carb back to trinity and they replaced the middle needle o-rings but that didn't help.