1974 13B Rotary Pickup (fresh motor pro built - not by me) street ported, 1982 electronic distributor, side draft Dellorto. Cranks and idles great but won't run above 1600 RPM.Carb rebuilt, no clogs, float adjusted, no vacuum leaks, tried running it on a fuel bottle, no changes. Timing is set to factory, fresh plugs, wires, coils, no change. Tried adding starter fluid while idling and it stalls, I was told this eliminates fuel issues and points to ignition.

Any thoughts?

 

if you go to give it gas and it falls on its face it is probably the accelerator pump not working?

 

Thanks,
It could be but when I shoot starter fluid into the carb while opening the throttle it stumbles. It seems like the aerosol shot would act like the accelerator pump.

I'm still stumped

 

I agree ...I suspect ignition. Timing isn't advancing. Double check under the distributor or, if you have the original (mechanical/vacuum advance?) try that.

 

Thanks,

That's an idea.
I'm using the same set up that used to run fine.
I think I will try rotating the distributor after it starts and just as the motor stumbles.
Does anyone know the symptoms of a bad igniter?
My timing light indicates all plugs are getting a signal even as it stumbles.

 

bad igniter means no spark so check if its leading or trailing igniter. also, be sureyou installed the dizzy at tdc (best is to use the flywheel trick) and check the accelerator pump diapram (bottom of the carb), it could be shot. hoss the plugs? wet or dry?

 

Check your plugs. Dry=carb problem...wet=ignition problem.......I think....maybe....something like that.