I started tuning my e50/polini/casematched/4-reed/race crank/dellorto 19 this weekend and I have a couple of questions for you rad tuner dudes.
1) Put bike up on stand, warmed engine up, set idle highish, and then set my mixture screw. Seems best at about half a turn out. Does this mean I need a smaller idle jet so that my mixture screw can come out another half turn or more?
2) At any jet that I tried from 103-118, my engine would sputter and run real rough when I tried to go past half throttle. I left the 118 in and started playing with the needle settings and the only way I could get up close to full throttle was with the needle (a W7) set in the leanest position. Still sputters now from about 7/8ths-throttle to WOT but I figure that might be due to the 118. Does this mean I need to try a different needle? I was thinking I might need to get a slightly fatter needle. W8 has a taper 3mm shorter than a W7 or else the W10 needle which has a 3mm shorter taper also, but in additon to that the tip has a diameter of 1.8mm compared to the 1.4mm tip that the W7 has. Does that sound right to you guys?
I haven't plug chopped yet cuz I can't WOT, but my plug is starting to look a little better over-all with the 118. I might even want to go richer, but I'm not sure if that roughness at near WOT is because of the big jet or the fact that it still wants a leaner needle.
Advanced-tuning advice greatly appreciated here.