Tried a new pipe and picked up but it a bit strange on jetting. It is a Polini Corsa race pipe.
Using the same 98 jets it ran previously 54 (57.9 with fairing), it ran 57.4 so a quick gain already, and it was very responsive. This is with the 21mm OKO. I put in a 102 jet and it acted very rich before hitting the power band, 4 stroking, but when it hit, it picked up and ran 57.9. I put in a 105, the pre-power band got much worse and almost wouldn't get on the pipe, but when it hit, it bumped up and ran 58.4. With the fairing that should be 62-63. So, it acts like it wants more jet, but has trouble getting on the pipe when I give it jet.
As a note, the clutch is engaging about 5200 and then peaking about 9400 before the CVT pulls it down. It runs top speed about 8800. I run a yellow Malossi center spring on a stock clutch housing with the lightest of the Polini outer clutch springs, giving me the 5200 engagement. It has a Ruckus Malossi variator with 5.6g weights.
I have not opened up the block for the bigger boost port as I was planning to go back and forth between the 50 and 73cc jugs, but I know this is one more piece holding me back so I will probably port it after this weekend in Ohio and see how it likes it.
I tried to part throttle it and see if I could get it on the pipe before going past 3/4 throttle and getting into the main jet, but it didn't have enough power to get up there. What is your best advice? Lower the needle or try a bigger one? Or???