Rebuilt a YF 2100 this spring I’ve had sitting around for a few years. A whole lot of family life and competing hobbies kept me from installing and running until just today.

The B it replaces was in pretty good repair. No warpage leaks from what I could tell. Also rebuilt by me a few years ago. A bit of throttle shaft wear but not too bad.

The little stumbly miss at 1000-1500 rpm’s is now completely gone. Engine will idle smoothly at some absurdly low RPM that was impossible with the B. I was too lazy to hook up the dwell tach to measure it.

The B was much more finicky to adjust with the idle mixture and curb idle screw. Had a definite sweet spot you had to find. I really can’t make the YF run badly or make it stumble on transition, unless I do something pretty extreme with the mix screw. The 1.5 turns I started out with is just about as good as it gets.

1951 3100