Chris:

On r/c cars the idle has to be set with the screw on the carb as the backwards motion of the throttle servo is used to operate the brakes. And you can't set the carb using the same method you use for a plane.

hopeless:

It's not hopeless. (Sorry, couldn't resist) As Chris said, set your high speed to peak, then back it out until it just drops into a four cycle. You CAN NOT peak the engine and expect it to run well on a car. Bring the engine back to idle, then nail it to full throttle. If it comes off idle with no problem, then run it and see how it sounds. If it just dies when you nail it open the idle screw just a little bit and recheck. You want it to burble just a little bit and then come on, or accellerate cleanly.

In addition to not cooling when you're sitting still, you don't have any load on the engine - you have to run it to check the mixture. Should burble at full throttle with the wheels off the ground, and pick up clean when going on the road.

HTH.

Bill.

PS: You have to do all this pretty fast because you aren't cooling when you're sitting. wr.