What I'm looking for is a little advice on performance improvements, but I'm not interested in having to tweak every change of season. My 2009 TW resides at about 2500 - 4000 ft altitude... in the Appalachian mountains. Purchased in South Carolina. I have the stock jetting, which I think is #125... is this correct #? What I find is that the bike takes long to warm up, maybe indicating lean mixture. I've read about the "popping" during decel indicating a lean mixture, but higher altitude provides richer mixture. I'm just a little confused. Anyone have any advice based on my altitude? Should I try going richer with #128? Is an exhaust change worth doing? I've read qwerty's post on carb tuning, just needing some clarification and personal guidance if anyone has two cents to offer. I'm not looking to make the bike into something beyond its intended purposes, just get the most out of the 196cc, but also don't want to compromise fuel economy.