TOPIC:

Please for help.
Engine running not smoothly during ride about 3700-4000 rpm - irregular running.
Carbs are cleaned, balanced, checked. New ignitions coils and spark plugs. On center stand running well, problem is only during ride when throttle is little opened. If throttle is open quickly, problem not exist. Ihave KZ1300 1979 production's number 200.

Check your diaphragms carefully for cracks/perforations!  The slightest vacuum leak caused by a damaged diaphragm could be the soure of your problem. A defective diaphragm will not maintain the (consistent) vacuum required to hold the sliders/high-speed needles in their required postion.Based on your explanation; When the throttle is opened quickly the sudden vacuum is sufficient to lift the sliders..... so the engine revs-up normally. However at cruising speed, a defective diaphragm will leak and not maintain a stabilized vacuum that would normally hold the sliders in the correct position. The affected sliders/needles will drop, causing those two cylinders to run Lean.