Engine potential
 

After rebuilding my engine I cannot get over 5k RPM, it starts missing badly. Before the overhaul I could get over 7k with no cutting out. I'm running 12 degrees advance. I've replaced my stock fual pump with a Holley blue electric pump. Any one got any Ideas on why I can't get any higher on my RPM.
Also this is only under a load, because I can sit in the driveway and rev it over 7 k and it doesn't cut out at all,,,just when I try to run it hard down the road.

Re: Engine potential
 

Are you sure it is ignition? Was it doing this before the pump replacement?

Re: Engine potential
 

Does it backfire through the carburetor? If so it may be jetted lean.
Or it could be related to too large of a carburetor. When you hammer it on the road the engine sees a large volume of air and if there is not strong enough a signal it may run lean until rpm catches up.

Re: Engine potential
 

I would take a look at the accelerator pump to make sure its working correctly

Re: Engine potential
 

well i wouldnt blame it on the ign system cuz it will work in the driveway.i wouldnt blame it on the carb being to big because that would be more of a problem in the lower rpm rather then the higher rpm and as far as accelorator pump that would be a problem with throttle response because it only pumps fuel when you press down on the gas and doesnt do anything if your just wide open in a gear.now it does sound like its running outta fuel by the way u explaned other then the missing it would have to be pretty lean to miss.i would go thu the bassics and check your float levels make sure theres no vaccum leaks.one thing you can do is get a vaccum gauge and plug it into manifold vaccum, tape the gauge to the windsheild and see where the vaccum level is when its breaking up that will tell you if its running lean or rich