Cant accel faster than 6000 rpms on my 1999 600 susuki katana or you can say cant go faster than 75-80 mph it starts to stall or bog out i think

yes, the clutch plates are starting to wear out, thats one of the first signs. It'll just get worse at lower speeds. replace the plates theyre cheap for a 2000 katana

When going about 50 mph, turn throttle fully open. If clutch is slipping, engine will rev but speed will not increase very much.

check for a vacuum leak around intake manifold or any hoses going off the intake. if you cant get at .the vacuum hoses of try pinching them and see if rpm goes down.

Not everyone on here is an expert! Some of us are just brave enough to try stuff instead of taking it to or calling "the guy".Hey--this help is free! If you don't like our answers TAKE IT OUT OF OUR PAY!

unhook the mass air flow or have it checked thats what i think is wrong with mine i cant idle without stalling above 2 rpms.

There is a vaccum fuel valve, that shuts off the fuel when not running, if that line has a crack or leak it will not let fuel into the carb.
The only thing I can think of w/o more info

You need to check for exhaust back pressure--no more than 1 LB pr 1000 RPM.
One other problem-check amp draw on fuel pump-must be at least 8 amps or pump is not up to snuff.

sounds like catalytic converter to me




james ray

7k is where the main jets kick in in the carbs i would guess they are plugged somehow here is a free service manual download also check out www.katriders.com and type carbs 101 in tthe search box http://rtcdesign.com/gsx600f_manual/GSX600F.pdf

Pull the MAF off and see is the wire across it is clean. If it's clean, not the problem. If not clean, go to auto parts store and get the spray cleaner just for this situation and clean it. That wire has to be unobstructed. It regulates all fuel flow as air passes over it from the butterfly/throttle valve.