Idle adjust on an 83 KZ550 - what did I change?

I think this might sound strange to some people, but the engineer (and student) in me wants to know... when I adjusted the idle (using the knob) on my 83 KZ550, what exactly what I changing?

Mine was idling around 2000rpm... we've got it doing 1000 now and it changed the idle, but also engine braking and other things (sound, etc). Did I change the carbs by doing this, or what exactly what changed?

Thanks all,
Dustin

Hey D...
You lessened the air and fuel flowing through the carbs and slowed down the combustion in the engine.
I'm sure engineer and student of the scoot types will chime in with more detail. :laugh:
Here's hoping all is well with you and yours.

Those things are the CV Tekei carbs? The idle knob hits a stop on the bellcrank which is the thing that the throttle cables connect to. The bellcrank, in turn is attached by rods to the throttle butterflies. The throttle butterfly on a CV carb is open an eyelash at the correct idle speed. When you turn the knob in, it opens the throttle butterflies just a tad to allow more air through which pulls more fuel through and raises the idle speed. When you close the knob, it does the reverse. If the throttle butterflies are completely closed, the bike will not idle.

Definitely DV carbs, per the books I have. Thanks to both of you for helping me understand what was going on.

A friend had told me it was adjusting a cable, but that didnt make sense until I got the description of the butterfly. I understand now why it not only idles slower, but increases engine-breaking too.

oops please delete this post

Post edited by: loudhvx, at: 2007/06/27 11:28