Subtle lope or lug w/50 Starlight

[50starlite]

I drive my 50 Starlight 50+ miles, at least once a week. Some stop and go city driving, and some 60mph bypass. It starts and idles as it should. It seems to run just fine until it gets up to temperature. On acceleration it seems to run as it should, cruising at a steady speed I have a problem. It seems to have a subtle lope or lug. Plugs and points have about 2k miles. Any suggestions?

Thanks, Dick

[Lothar]

Could it be running a little lean, Dick? Maybe your carb float level is set a little low?

[50starlite]

I replaced the carb with one I rebuilt last winter and that solved the original problem, but..........now it stumbles some only when I give it gas, like from a dead start. cruises just fine. I think I just traded one problem for another. Maybe the float needle or seat?

[rockne10]

Accelerator pump?

[50starlite]

I'll drive it a while and if it doesn't straighten out I'll get back into the carb.

[Bud]

I would say to check the accelerator pump as it sounds like there is little or no output from it. Sometimes you can make minor adjustments to the accelerator pump rod to get a little more squirt from the accelerator pump. Bud

[studerodder]

an intake gasket leak will give this symptom, leaning out one or more cylinders during light throttle or cruise. another indicator of this condition is "runs good cold, but has a lope at idle when wamed up"

[zoegrant]

Vacuum leak ?