ORIGINAL: Osirisf16
If the tank is higher than the fuel needle, and the plane is flying at midair, can the engine stall or something?
No.
The fuel tank height issue is overstated too often here.
It is suggested that the tank height be about the same as the carb needle height to prevent siphoning.
Siphoning is annoying and can also lead to hydro lock.
But the height does not affect engine performance.
Otherwise we would never be able to fly our planes with the nose pointed up or down...
ORIGINAL: Osirisf16
And why set the throttle at high when you are going to start it? That definately stall the engine because the flow of the fuel into the carb will be many.
No need what-so ever.
It's a good idea to open the throttle to prime the engine first, then bring the throttle back to idle.
If the tank height is not equal to the carb, then leaving the throttle at a high setting actually exacerbates the siphoning problem.
Fuel will flow back into the tank FASTER ( if the tank is lower ) or into the carb ( if the tank is higher ) causing starting problems.
Normally on the inverted engines I merely open the throttle, turn the engine over a few times while either holding my finger over the exhaust port or the carb intake ( to pull fuel in ), then bring the throttle back to idle ( so that the fuel does not flow back into the tank ), then quickly affix the ignitor and hit the spinner with the starter.
That's the only difference with an inverted mount!
ORIGINAL: Osirisf16
Another idea is to have your plane at inverted position when you are going to start the engine. How about that?
Not needed at all.
If you feel you need to do that, either your engine is mistuned, you have fuel flow issues, or you are not doing things properly.
I run the majority of my engines inverted w/o any problems and I have a bunch of them this way.