Motorcycle Repair: 1994 yamaha yzf 750, yamaha yzf 750, carburetor problems

Question
Hi, so im just getting into bikes i dont know that much at all about them but im tryin to learn. My question is about my 1994 yamaha yzf 750 70% of the time it doesnt want to go past 4000rpms but sometimes it will. but of course its getting to be a pain cause its not fun to ride like that. ive been told its the fuel pump  what might be your thoughts on it. if i can provide you with more info to help you out i would be happy to do that  thanks for any help johnny  

Answer
Hi Johnny,

Get a copy of the service manual (repair manual) and learn about basic maintenance, troubleshooting, and repairs. The manual will pay for itself with the first work you perform.

When describing performance or carburetor problems, use throttle opening positions instead of engine speed (RPM). Example: "The engine bogs and stalls between 1/4 and 1/2 throttle." Engine speeds are helpful for fine tuning.

Check the airbox and air filter. Clean or replace accordingly.

Check cylinder compression to learn the condition of the engine.

If the MC was stored for periods and/or the engine has not been started for periods, inspect the carbs and fuel system for evidence of fuel varnishing (gumming).

I suspect a problem within the exhaust valve or the valve servo motor.

Respectfully,
Mark Shively