Fisrt, let me say that I broke a lot of rules by changing too many variables at one time. Also, thanks Monty! 1) Added 12 oz flywheel weight. Tried it today and can almost lock up rear break without stalling and with clutch fully engaged! 2) Added Ty Davis Hot Start system. Bitchen. 3) Had Yamaha shop set timing to YZ specs and adjust jetting. Dropped down to 175 main and will tweak from there. Tomorrow, I will take it out and open it up to test new timing. Also, played some more with my E-series. First, I went down to 4 disk. Which according to White Brothers is like stock. Took it for a spin then came back and added 4 more disk. WOW, what a difference. I could feel it right off the bat. I didn't get a chance to really open it up but, up to 1/4 to 1/2 throttle huge difference. It just seems to build RPMs quicker. I normally ride with twelve disk and have ridden with with 7. So tomorrow I'll try it with 8 and the YZ timing . The next time some yahoo says that the stock pipe is just as fast as my WB with 7 to 12 disks I'm going to tell him to stick it where the sun don't shine! I'm doing my homework and it just aint so! Sorry. But, I also learned that it is rideable with 4 disks and very quiet although not as firey as one would expect from a good performing WR. So if I am ever at a place where that becomes a necessity I'll just remove 4 disks and be good to go. To me that is a huge selling point of the WB E-Series exhaust. It is easily adjustable and still kicks. Disclaimer: these are just my opinions from trial and error testing. But, I am always willing to learn from the experience of others. Paul.