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Discussion Starter #1
Pretty new on this bike so I am not familiar with too much on it. It is a 1991 Suzuki GSX750F, supposedly has the GSXR motor in it, but I'm thinking he just said that because they have the same motors as the late 80's gsxr's. Yoshi pipe and jetted. My problem is the number 4 cylinder. I've been changing spark plugs to see whats going on with it and after I change them it will run perfect for maybe 15 minutes then I lose spark in the number 4 cylinder and it starts running bad again. My thought was that it was getting too much fuel for that to handle and just keeps messing stuff up. All other cylinders are fine and perfect. Like I said I just got this bike and the guy had supposedly just went through the carbs and 'rebuilt' them and cleaned them. Is there any like adjust screw on this carb that I can maybe turn it down? Maybe even a higher burning spark plug I could use to get by? I don't have the time or the money to completely take apart the carbs or bring it somewhere to have it done.
PLEASE HELP!
 

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OK, that means it is too rich. Check the fuel level in the carb, followed by the idle air/fuel (pilot) adjustment. Newer bikes tend to have that adjustment screw under a brass plug, so you don't mess with it.

The fuel level can be quickly checked by attaching a clear tube to the drain and curving it up the side of the carburetor, then opening the drain with the fuel petcock open or on 'prime'. The tube will show the fuel level directly, so you can compare the rich one with the others.
 

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Discussion Starter #5
Okay thanks. Is the idle air/fuel adjustment the screw with a spring under it? I'm not too familiar with bikes, I am a automobile mechanic lol. Is there any sort of diagram I can find for these carbs?
 
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