New bushing, new distributorHmmm I wonder if its related to your timing issue?
Idles good but not good under load?
Dist bushing worn? Bent shaft?
I need to check all the filters front to rear. Meant to do that before I fired this new engine. Got excited and ahead of myself.Back in the 70s I had a Duster that did that. Turned out to be the prefilter on the pick-up in the gas tank.
This. Surging is usually related to a fuel delivery problem. I had it happen when my later year (70+) tank venting system wasn't hooked up properly. Pressure would quickly build in the tank and cause surging.Back in the 70s I had a Duster that did that. Turned out to be the prefilter on the pick-up in the gas tank.
I had one of those carbs on my 340, did the same thing. I swapped out for a 650 double pumper I rebuilt and it went away.Carb is holley 670 street avenger. Engine is a 340 that made right at 400 HP on the dyno
I just happen to have a fresh 650 double pumper on the bench. I will give it a try.I had one of those carbs on my 340, did the same thing. I swapped out for a 650 double pumper I rebuilt and it went away.
Thanks for sharing that info. But it has a new Cloyes true roller double roller chain and gear set.I'm positive this is not your problem, but I had the same symptoms and it turned out to be the stock plastic timing gear was so chewed up and out-a-round, the chain was flappin. Especially when 40+ mph at cruising.
Thanks for sharing that info. But it has a new Cloyes true roller double roller chain and gear set.
MSD distributor, no vacuum advance.unplug the vac advance hose on dist if you are running one . it should run smooth as a kitten. Had same issue with a commando with big cam .