Here is a little tool I made for tuning my 50cc Brison engines(forward facing needles) while running. Although it only works safely with the engine at idle. Too much wind and vibration at high rpm.[X(] It does save the aggravation of shutting down, adjusting and restarting.

One of the main reasons I switched from glo to gas was always retuning the carb on the glo engines. When I get my planes out this spring, I first check the tanks, the clunk, fuel lines, fill them and fire them up, if they pull the rpms they are supposed to, I'm ready to fly. Do you retune your engines every flight? Chances are good I won't have to touch them all summer. As far as cowl on cowl off, I'm only running 50cc engines and the head is hanging out in the breeze, as I have stated before, I have never lost an engine because of a lean run.

Dale