(1) I'd T into the fuel line & see what psi you have "at speed" when it acts up. (2) Will it rev up normal like you want it to in your driveway? on the second suggestion, the fuel requirement wouldn't be the same cuz of the minimal load but you should be able to load it ign wise pretty good by gunning it to pin it to ign or fuel. keep us posted. & when it acts up does it spit & sputter or wont go any higher but is smooth or something else?