[HwyStarJoe]

Will a power valve that's been backfired cause a bog or a hesitation when you attempt full throttle, but run normally just driving around?
Trying to tune a full throttle hesitation out but can't seem to get it. I suspect a blown power valve.

What else can I look for? I've ruled out vacuum leaks.

 

[HwyStarJoe]

Well, the timing is a guessing game right now..... the engine this carb is on doesn't have a timing tab. My next step was going to time it from scratch, watching the valves and using a piston stop.
I wanted to take another look at the distributor.... points type. Might be gunked up.
I think I can eliminate the power valve then, because it idles and runs fine... not too rich and no smoke.
Thanks Everett