Motorcycle Repair: 1982 honda cb750f supersport, honda cb750f supersport, old bikes


Question
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Mark,

After riding my bike for a few miles, when I get stopped by a red light, I just let my bike sit and idle while the lights red.  When the light turns green and I give it some gas, the motor surges and sometimes dies.  It idles at about 1000 rpm's, but when i touch the gas, it drops to about 500, then it revs like it should.  Also while riding normaly, if I gear it down and accelerate heavly, it skips a little.  THe bike has 30,000 miles on it, and i am the third owner. It also idles kinda funny.  I dont know if the old bikes are supposed to sound like a new one while its idling, but it sounds different.  Thanks for your help.  My email is windela10@yahoo.com

Answer
Hi Windel,

It's hard for me to diagnose the problem without being present and performing a few checks.

Use throttle opening positions when describing carburetor related problems. i.e.: Engine bogs down ansd stalls at about 1/4 to 1/2 throttle. Carb circuits operate at specific areas of throttle openings and are tuned accordingly.

The carburetors may need tuning, cleaned, and/or synchronized.

The air filter may need cleaned or replaced.

The engine may need spark plugs and a general tune-up.

Check cylinder compression to learn the condition of the engine.

Get a copy of the service manual and learn about tune-up procedures. It's not too difficult to do at home with a few tools.

I'll send tech files to your email.

Respectfully,
Mark Shively