Motorcycle Repair: Rough Idling, kawasaki kz550, leak air

Question
Chris,

I have trouble with my 1982 Kawasaki KZ550 in terms of getting it to idle. It seems to idle fine with the choke on however when I take it off, the motor seems to bog down. I try to adjust the knob on the top of my carburator that seems to adjust the throttle however now the idling is worse than I had it before. How can I adjust the idling so that things will get back to normal? At what RPM should the bike idle when the choke is on fully? Please send me any ideas and help! Thanks E-mail: BurkettEagles@aol.com

Answer
Hi Jeff.

It seems as though you may have other issues that are causing this problem.

The only knob on the carb that you should be touching is on the underside of the carb set.  Usually in the middle of the assembly.  Any other screw that you touch will mess with the synchro.

Start by checking having the carbs cleaned if the bike has spent any time in storage.  The carbs also need to be synchronized properly.

Check all of the connections from the carbs to the manifolds and from the manifolds to the engine.  They should be totally air tight.  Then check the manifolds for cracks.  replace any manifolds that you find that are damaged.  They will leak air and mess with the idle and mixture.

Check the compression in each cylinder.  You could need the valve adjustment done or new valves and/or new valvesprings.

Check the connections from the exhaust headers to the engine.  If they are loose, then tighten them properly.

The idle should be in the 900rpm - 1100rpm range, if memory serves me.  The bike should not be running with the choke on unless it is stone cold, then it should run at normal rpms til it warms up, then it will idle faster and, if left alone, will foul the plugs.

Start with that and let me know what you find.
Good luck and ride safe.
FALCON