Engine starts, runs and idles without problem. Take it for a drive and it doesn't get smooth power between 3500 and 5000rpm and is jerky. Feels like engine it is shutting on and off very quickly. Not smooth at all.
Engine builder suggested checking the timing and gave me instruction.
Have timing light.
Question is:::
How exactly do you time leading and trailing on an old school single electronic distributor? I did search for this on this site and others. Realize it may be a silly question, but want to get it right. Distributor is not locked.

 

Check off of the #1 plug wire for each ignition system.

I don't really see how ignition timing could be causing this but it's still a good idea to know where it is at. Make sure to check it at varying engine speeds so you can see what the ignition curve is. (Disconnect the vacuum hoses if present when checking)

If/when you adjust it, you rotate the distributor to set the leading, then slide the trailing vacuum can in and out to set the split (can out = less split). Trailing can is the one with slotted mounting holes...

 

Thanks,

What do you mean by check off #1 plug for each ignition system please?

Also if you do not think it is ignition, ( without seeing / hearing it ) what do you suggest it could be?

 

Sounds like your fuel/carb is the issue

 

yeah if it goes very rich under heavy load make sure a jet isn't loose. this has happened to me before.