Fhead Running Rough

Absolutely no point to messing with the carb or anything else until you are sure the ignition parts are in good condition, and tuned to spec.

Back in the day, there was a specific sequence of tuning to be followed prior to any diagnosis.

It might BE the carb, but the difference is between hoping for luck, or using logic.

 

Never heard of timing gears jumping on an f-head.

I assume by "gone through" you include setting the points and timing. And while timing it did you verify that the advance mechanism is working? (Does your jeep have a vacuum advance?)

Is the distributor shaft and bearing worn/loose? That would make the point gap and timing (dwell) inconsistent.

Simple old fashioned dwell meter and basic timing light would be good to use, and can reveal much.

Possible a condensor going bad. New ones have a bad reputation.

 

Define "running rough". Runs smoothly out of gear? Runs rough in gear?

 

I had a worn timing gear in my motor, the rotor would jump a little, you could see it and hear a click when turning the motor over slowly. New fiber gear fixed that problem.

 

As a novice mechanic in the '60s one of the best bits of advice I got from a seasoned pro went something like this:

A carburetor is a completely passive device that is affected by, and responds to, the systems around it - points gap/dwell, ignition timing, coil condition, spark plugs and wiring condition, cap & rotor, valve clearance, compression, vacuum, fuel supply (and quality), air supply. Make sure all that stuff is right before laying hands on the carburetor.

 

Put the number one plug back how it was and try it. It should run on two cylinders while you can get timing measurements off of #1