ok here are some stats of the bike im just lookin for some advice

99 gsxr 600
full yosh
jetted

problems
i have a flat spot at 4500 where if i try and cruise the bike bucks ...
and at 10k ill be getting on it and like at 10k the rpm needle like drops then bike picks back up
and the gay backfires

i know i fucked up cause i paid the guy who works on all the local bikes $400 for jetkit / installation and tune ... now im out 400 with a shitty running bike

just wondering if anyone has any ideas so when i goto this certified mechanic i can tell him where to start or to look thanks

sounds like your jets are giving too much gas (too big) or your carbs need sync'd

chris

The 4500 flat spot will be hard to get rid of as you have a full system, they lug down low until you get the revs up and it goes away.
The 10k problem sounds to be to rich of a mixture as I had the same problem. I leaned it out a bit and it was fine.

A general rule for lean motors, at steady rpm cruisng, the bike will surge slightly and run hot. to rich would be you haveing to keep adding more throttle to keep at the same speed.

Have your tech go down a size on the main jets or lower the floats 1mm.

If u paid 400 buck for that one guy to do it, and it runs like crap, you should of turned right back around. I would go conplain and tell him it better be free to fix.

D

already well thanks for the suggestions im taking it to that guy today and telling him free fix or ill blow up his house http://www.gixxer.com/forums/images/graemlins/mad.gif lol jp .. ya it was $100 for jetkit so i paid like $300 for a tune up ill let u guys know how it goes and ill suggest to him what u said about the jets and float height thx alot man

One more thing..
Before you go back, make sure your air filter is clean or new.. a dirty filter will cause the engine to run rich.