I've always heard good things about the E3's. Never tried them. From detailed comparison tests I seen on various engine building TV shows, every time they run a fair controlled test E3's make a bit more power than other plugs. I'm skeptical this would be noticeable (measurable) on an stock (1) cyl TBR7 but, I've often been wrong. When you move to 4,6, & 8 cylinder motors, built for performance, is where performance plugs really shine. That said, I'm not discounting the value of longer life and the piece of mind that brings. I'm going to start with the NGK D8EA gapped as stated in the manual to start with. Then consider the CDI, wire & boot upgrade down the road. Mostly because they had (2) in stock at the Autozone on the corner and I'm lazy and want to move on from the spark plug thing