Motorcycle Repair: 1980 Kawasaki KZ750 Carburetor problems, kawasaki kz750, carburetor problems

Question
Hi Chris,

 I just bought this bike. It was sitting a couple of years.  I cleaned the carbs.  All the parts looked good so I just cleaned them.  I oiled and adjusted the throttle cable, and cleaned the fuel tank and filter. It idles fine. When I give it throttle it rev's up nicely, but when I release throttle it won't go back to normal idle speed.   What do you suggest could be the problem?    thanks

Answer
Hi Jim.
 It sounds like something either in the cable or the carbs is sticking open.  When you cleaned the carbs, did you disassemble them or clean the parts you could see.  Sometimes that is enough, but for a bike that has been sitting for a long time, the carbs need disassembly cleaning.

 There are a couple of other things that it could be and that is;

1)  The cable is adjusted too tight.  Check the free play.  It should be approximately 1/4 inch of free play in the throttle (30-40 degrees of turn).

2)  Because it is old, there is a strand of the cable that has broken and is catching on the cable sleeve so the cable needs to be replaced, which is best for a restoration anyway.

3)  Throttle arm (where the cable connects) on the carb is sticking.  Check the movement of the mechanism.

Start with those and see what you find.
Good luck.
FALCON