[Capri306]

Well, reading the plugs has worked well in *most* situations for me. However, to know for sure I would find an exhaust shop with an infrared exhaust gas analyzer and see if they would help out. Of course, that would only do you good at idle. As far as the jets go, I'm no longer in the "carb loop," so to speak. I don't think you're going to hurt anything going a couple steps up in jet size, though. At least, to find out for sure.