Thank you Lucifer I probably know why I had a mechanical defect... I had an air leak because of the rubber manifold, I couldn't find it and because of that I seized 3 times :haeh: Then you also have to know that the cylinder was overbored in its last size... Heat, mechanical stress and thin skirt should explain the broke :wasntme: As for my experimentations, I put the 130 main and at the same time I put an AV264. It was too rich from 1/3 to 3/4 of throttle. Then I put back my X2 needle clip to the top position, it was much better, but still "4T-ing" from 1/3 to 1/2 of the throttle. So, I put back the CF262 (=AV262 (?!)), I put the needle clip to the 2nd position from top, and I will tell you tomorrow ! What I am affraid of is that the Leo pipe delivers a "weak" signal at low RPM, so I adjusted the jetting to have a smooth city-ride (low and lower-mid-RPM), but because of that, I may run too lean at "upper-mid-RPM" without knowing it... What do you think ? I am still running 17-18° of timing advance. Actually, I don't want to gain revs, I want torque ! Not that easy with the Leo pipe, but that's probably one of the few that can be mounted on an 8" scooter without touching (driving solo). Is there any tweak that one can do to this pipe in order to gain torque and loose some power at high-rpm ??