"The motor starts and runs gre
"The motor starts and runs great for about 20 minutes at WOT, then all of a sudden seems to drop cylinders (slows down, vibrates). If I reduce the throttle to about 1/3 it runs fine again. After sitting and allowing everything to cool, it runs great again until it warms back up. I replaced the plugs and put a spare power pack on. No help. I tested the coils and plug wires cold and all were within service manual limits. They were tested cold though. I have ordered new coils as a precaution. Any ideas?"
"The motor starts and runs great for about 20 minutes at WOT, then all of a sudden seems to drop cylinders (slows down, vibrates). If I reduce the throttle to about 1/3 it runs fine again. After sitting and allowing everything to cool, it runs great again until it warms back up. I replaced the plugs and put a spare power pack on. No help. I tested the coils and plug wires cold and all were within service manual limits. They were tested cold though. I have ordered new coils as a precaution. Any ideas?"