powellskier
CB750 Member
I own a 1980 CB750K w/ Vetter with 34,000 miles that I have been working on for far longer than I care to admit.
(I also own an identical motorcycle with around 23.000 miles.)
Without getting into too much detail, my problem is this: I cannot get this thing to idle. I have rebuilt/replaced the carbs twice, checked and rechecked valve clearance (.004 - .005) and run compression tests. Compression numbers are a bit low, but all my tests have been done when the bike is cold. The compression numbers are slightly higher on the 23k engine.
While syncing the carbs with a mercury sync tool, I noticed that the 34k engine draws half as much mercury as the 23k engine. This tells me that my intake "suction" through the carburetors into the engine may be why I am having so much trouble running it at low RPMs. What do I need to do to remedy this problem? Do I need to tear it down and check the rings and seals + cylinder and piston tolerances? Any advice would be greatly appreciated.
(I also own an identical motorcycle with around 23.000 miles.)
Without getting into too much detail, my problem is this: I cannot get this thing to idle. I have rebuilt/replaced the carbs twice, checked and rechecked valve clearance (.004 - .005) and run compression tests. Compression numbers are a bit low, but all my tests have been done when the bike is cold. The compression numbers are slightly higher on the 23k engine.
While syncing the carbs with a mercury sync tool, I noticed that the 34k engine draws half as much mercury as the 23k engine. This tells me that my intake "suction" through the carburetors into the engine may be why I am having so much trouble running it at low RPMs. What do I need to do to remedy this problem? Do I need to tear it down and check the rings and seals + cylinder and piston tolerances? Any advice would be greatly appreciated.