Good afternoon,
I have a problem with my RCGF 20cc: the idle is too fast. This evening I will try to replace the entire fuel line and check if the throttle butterfly is too loose. Throttle servo is ok.

Last chance I can change electronic ignition and carburator. 20cc has the same carburetor of the 15cc?

Thank you in advance

Andrea

It has been a long time since a question like this has come up. The stickys above this forum have a great deal of info on common problems.
I recently had a problem with a plane I took down from storage (about five years). The problem was the regulator diaphragm was now stiff and holding the needle wide open.
I replaced the diaphragm problem solved.
So look through the stickys and go over some common issues. When I am setting my idle I often put a idle stop screw in (temporarily) so that I know the butterfly valve is very close to the idle jet to start.
Keep us involved with an update please.

Walbro K1-WYTA upgrade spiral kit
The same carb is used on all these: https://www.rcgfusa.com/product/stin...6cc-20cc-twin/

The carb is a Walbro WT 1183, I just ordered the upgrade regulator diaphragm for mine.

https://www.rcgfusa.com/product/stin...6cc-20cc-twin/

They use the same, WT1183, on the 10, 15, 20, 26 and 20 twin.

Walbro WT 1183-247, I don't know what the 247 designates.

You remember how the nitro engines would rev higher right at the end of the tank, right? As it runs out of fuel, the Nitros will have a strong increase of RPMS. It was our timer alert sensor back in the day that it was time to land... lol. What causes this increase is LEAN FUEL MIXTURE. As it runs out of fuel but the same amount of air is coming in it in a way starts running lean. Less fuel, less oil in fuel, same air. My point for this is check for air leaks if you cannot adjust the rpm any lower mechanically.
A few ways to do this...

1. tightens nuts, bolts, etc. look for change...
2. Next, start the engine and let idle as low as you can get it. (It's best to have a 2nd set of hands for this.) Grab a propane bottle and open the valve. NO FIRE NOT LIT>>> That is a different test lol. While the engine is running, let propane non-liquid gas flow into the carb's throttle body at the butterfly and notice the change in the running engine. Now move the gas tip to the gasket areas behind the carb and frankly anywhere 2 items meet and listen for the same change in sound. If you hear one, there is a leak.
3. If the butterfly is loose, it may be sucking air here, causing issues.

PUMP GAS will cause the diaphragm to wrinkle like the skin on a 75-year-old MELTONIAN lady (defined as a Galveston Island resident born and raised) that wore a bikini on the Texas beaches her whole life. The point is they get WrInKlEd... I have never had one cause fast idle, but I'll look for that from now on. It will cause them not to run or run poorly for sure.
We buy leaded gas; Google it. Someone close sells it. If you are not already...