[Rickracer]

Got a D&D slip on, and a K&N filter, originally had 130 mains (at least that's what they're stamped), and a mid range lean spot 3.5K to 4.5K, jet needles don't seem to make that much difference. My buddy drilled them to the equivalent of a 138 (supposedly), it would start missing @9K, and wouldn't turn over 11. Last night, put some 134s in it and now it pulls harder than ever on top end, right on past 13K, (yanking the front tire going into 2nd consistantly, which it didn't do before), but runs like crap 3K to 6K. Any ideas?

[SoCal94F2]

Jets are not just holes, there is a shape to them as well which determines their flow characteristics. Keihin and Factory Pro use jet sizes numbered by the jets flow, not hole size. Dynojet uses the hole size. Given that, RPM is not your best method of searching out a problem, but throttle position is. Check this link out for tuning info:

Musclecross Forum / Carb Tuning Guide - Symptoms and Troubleshooting

[Rickracer]

I should have been more specific, it was light part throttle in the lower rpm ranges that it was acting stupid, if I cracked it open, it would hesitate for a split second, then take off like a bat outta hell, then start breaking up badly at high rpms. I appreciate the link, I will study it thoroughly. I just set the jet needles on the 3rd groove with the 134s, went over the pilot screws about 3 times, and it's running sweet in the midrange now, and the top end seems as good as ever. We'll see if I made any real power difference next time I go to the track, which will probably be next Friday or Saturday night. Who knows, armed with more info, it might be running even better by then. Thanks again,