Well... you can't just start cutting up a sleeve like that and expect good results. The minimum you could have done was at least put a degree wheel on it to see what the stock timing was, and start working from there... in SMALL increases. If you just "eyeball" 1mm, you know nothing.

And if you're trying to make a Nelson out of a Rossi that way, you're in for a disappointment. There's a lot more to performance than exhaust timing.

Have you actually measured what rpm you are turning? Exactly what Nelson muffler are you using? If your engine has a hard time reaching the muffler's tuned rpm range, you will get tuning problems like you have now. You will be turning in that needle to get it staged on the pipe, but since the engine can't get there, you're starving it to death. This may well be the case if you are using the Q500 muffler. If you are, you may get better result from the Nelson" "sport" muffler.

Bring your engine along to the field next weekend, so we can have a look at it. (unless you don't want us looking ) I'll bring my degree wheel along, so we can at least have a look at that exhaust timing.

I know, I know... a little late. The race was last week, but there's always next time.