User Manual

RCGF Engine Tuning Tips
Tuning a gas engine is different than a glow engine. The needles work together. We recommend this
procedure for tuning the RCGF engines.
1) Start by turning out both the high and low needles between 1
5
8
to 1 ¾ turns.
2) Go full throttle and peak the high end with the high speed needle valve. When the engine sags you
have gone too far. Back the needle off 1 hour (
1
12
of at turn).
3) Go full throttle again and peak the engine using the low speed needle valve. When the engine sags,
back off the low end needle 1 hour (
1
12
of at turn). That’s right, peak the engine using the low end
needle. The reason is that the engine gets fuel from both needles once the engine comes off of idle.
4) Now bring the engine down to idle. Adjust the low end rpm idle using the trim on your transmitter.
The engine should not need any adjustment at this point.
The engine at this point should be almost perfect. It should transition from low to high speed without
any burps. If the engine does not run well after this setup look for an air leak, a bad reed valve, or
carburetor diaphragm problem.