About 6 months ago I replaced my failed coils with a pair of Accel 140403 Super Coils. Since then, I have chased my tail trying to tune the bike. Last night I decided to replace the fouled D8EA plugs (again). After reading up on the CB750 ignition system, it became evident that I needed resistance in the circuit. I bought D8ESL-R plugs this morning and the bike has never ran so well. Smooth, steady idle and power through the rpm range.