rough idle

Years after the project started, my 144 is finally running under its own power without me holding the throttle open. I set the timing with a vacuum gauge and tinkered with the idle screws. But it still doesn’t appear to be running “smooth”, and a minute or two after I took this video it...

I've been putting some good miles on my 1966 200cid Mustang this summer and it's been a lot of fun. Carb was rebuilt (Carter YFA) along with some other tune-ups in the spring and it's been running smoothly and reliably. Recently though I've been getting backfires while downshifting (3 speed...