No one around here can figure it out. I own a '79 with an '86 13B engine, that has a mikuni carb, full racing beat exhaust, after market fuel pump, that i've test to 5lbs. but when it's warmed up it cuts out about 6,500 rpm. If you let it sit for about ten minutes while it's still in operating temperature it runs great it pulls all the way down to 7,500 no problem. anyone have any ideas, any help would be greatly appreciated.

 

Sounds like vapor lock? Have you checked the fuel bowl to check for fuel?



(I did the camcorder under the hood trick... to check my fuel pressure a few months back. My fuel pressure gauge is on the side of my motor... and I wanted to make sure I had full pressure at WOT and 7K RPM).



If you aren't sure if it's electrical you could make some runs with a timming light hooked up. That would show that you have ignition. But it sounds like a fuel problem.