Mines a little too loose and the rpm wanders around in cruise. Anybody know how to tighten it up?

I call ACA anytime I have a question. (262)-534-6315 Friendly folks, easy to get answers fast.

Thanks 8GCBC, called them this morning and they were very knowledgeable and helpful.

Friction adjustment is on front throttle: remove knobs, remove cover (pull it away a little, there's 11/32" nuts on the back of the two screws). Unhook the spring under the top upholstery towards the front that holds the "curtain rod" of the bottom upholstery up. You can now pull down the upper part of the lower upholstery to expose the pivot bolt. Castellated nut, remove pin, tighten, reassemble. Mine has an ancient leather washer behind it to give friction, but ACA says that can be updated with more modern friction washers from them.

I must say I am impressed with ACA for parts support for their older aircraft, and for their friendliness and helpfulness.

Good question and Good work! Thank you for the details. I am a low time Scout pilot trying to learn more.