Gsxr 750 revs up and down very slowly?

So just picked up this gixxer, 1994 750, sweet bike, wasn't running when I got it, cleaned the carbs, new battery and it fired right up, but I feel like its not riding right, I cam make it through the rpm band, but not as fast as I'd like or expect, honestly it doesn't feel like the bike starts to pull at all until about 7k rpm

Pretty sure I'm very lean, will need to pull the plugs tonight to check, but the bike gets very hot after short rides, doesnt help that the radiator fans won't kick on, and when its warmed up have some serious popping on decel, plus I the rpm likes to hang up top for quite some time and come down very slowly.. sounds like its lean.. but the new symptom for me I've never experienced before is it revs up very slow, the engine under no load almost revs slower then it does with a load, so I can't do any of those quick throttle blips with a quick rev, don't know how to explain it other then it revs up super slow, but with enough time it'll get up there, wasn't what I was expecting from a sports bike, any ideas what could cause this? Lack of fuel? Or electrical maybe? I'm pretty sure the heads never been opened up, only has 20000 miles.. unless maybe its been so lean for so long and burned the exhaust valves? Uni air filter with a voodoo exhaust, which sounds sweet btw :) and I'm pretty sure its on stock jets

in my experience Voodoo exhaust are nothing but shiny noise. But to make that exhaust work a Factory Pro jet kit will go a long ways to making it happen. I doubt valves are burnt. Stuff is made tougher than it used to be and Gixxers are tough. Checking valve clearances won't hurt either.


The cooling issue is likely separate but related and could be just low on coolant for some reason. Check the level. If that checks out pressure test the system for leaks.

So i fell in a well for a couple months.. Anyways coolongs bad cuz my fan wont kick on, and ya i kearned how much performance you dont get from voodoo, rejetted the bike for an open flowing exhaust and it ran like crap.. It was way out of tune on the bottom and out of sync, bence the slow revs, but it still pulled up top, i went from a 115 main to 125 main and it lost quite a bit of power.. So voodoo is crap, i may just run straight pipe and jet bigger since the voodoo is still loud as crap

Oh and i synced them, shimmed the needles, pulled out the air screw and the bottom end crisped up nicely, if i would have left the stock mains itd be great

Always jet from the pilot up. Sort out the low speed and move up to the higher speeds. Jetting is additive which means all the circuits contribute at WFO so if the lower stuff is outta whack you'll never get the top end right and end up chasing your tail. I'll say it again buy a Factory Pro jet kit and follow the precise directions they supply with it.


I'm not just some guy on the 'net I'm a professional with 30+ years experience and 14 landspeed and 1 drag racing record on my resume'. Try the free advice and you should be surprised with the results.


Oh and if the fans not kicking on it's the fan switch. Test it. And checking the valve clearances wouldn't hurt either.

Ya i was shopping for a factory pro kit last night, will get one ordered soon

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