22 fzb

[John H]

Set the throttle stop screw such that the engine will run, but as slowly as possible without it stopping. Then adjust the slow running mixture screw to "peak" the engine revs. Too lean and the engine will slow down. Too rich and it will slow down. You are looking for the sweet spot in-between. When you've found it, slow the engine down with the throttle stop screw, again to run as slow as it will go without stopping. Then repeat the above. Peak the mixture screw. Keep repeating that process and eventually you should be able to reach a nice slow idle speed, without the engine stopping. The higher the engine speed, the less effect the slow running screw will have, so if it is miles out of adjustment, it might take a bit of guesswork to initially get it in the right ballpark. Turn the mixture screw slowly, to give the engine time to settle.

I hope that helps!