What exactly does the pinch test tell you on Nitro Engines? How do you do it? I have heard about it for a long time but never understood the point of it (or exactly what you do). Thanks.

you pinch the fuel line, and if it stays running for more then 3-5 seconds, the low speed is to rich. It it dies right away, the low speed is to lean. You want it to idle for 3-5 seconds and then slowly raise RPMS and die.

Thanks..