Sorry guys, I haven't been paying much attention to this forum lately as I just purchased a Burgman 650 executive and have been having to much fun "playing".
Any way, I did find out that the stock jet is a 110. When I contacted Kymco concerning what kind of jet to use, they told me that it is a Kymco jet, but you could use Keihin as well. Well come to find out that Keihin has several different types of main jet. So far havent been able to get an answer as to which one to use.
Re: the NHRC exhaust. I really like it. I have the carbon fiber model and it not only looks great, but gives the scooter a very throaty sound! It has an output orifice that is at least twice, maybe three times larger in diameter than the stock exhaust. Really lets the engine breathe, but like I said earlier, need to upjet to take care of the lean running issue.
I'll post back when I finally get this jetting issue taken care of.
Smoke eater