I have a 1983 Kz750, i've gotten it to idle pretty well, that was my first problem. My big problem is now, that at low RPMs the bike dogs if I rap on the throttle hard. We cleaned and inspected the carbs thoroughly, checked compression and adjusted the valves to achieve better compression. When idling we plugged in a vacuum gauge to one of the carbs, and the gauge flips back and forth wildly. Basically the gauge is showing that the cylinder is pushing back air reverse into the carb.

Any Suggestions?

I need help!

 

are you using a restrictor in the vacuum gauge?

 

Dragone,

Do you mean a Check Valve?

 

in the vacuum lines of the gauge or the gauge itself. A metering device.

http://www.z1enterprises.com/detail.aspx?ID=1695

 

we're not using any sort of metering device, I guess we should be! We did find that the chain had skipped a tooth on the crank gear, but it is not the problem. We've definitely narrowed it down to Carbs. by the way what is the purpose of the Pilot screw? and are the blank plugs on top required? The manual says that only US models have them.

 

Know your basic carburator circuits.
On the blank plug question, you mentioning the soft caps that are removed to adjust your pilot? They are not needed after you have removed the caps.