Motorcycle Repair: 50cc honda clone carb., slide cutaway, 50cc atv

Question
I have a 50cc ATV(Chinese) with a Honda clone engine(The old trail 50 motor) The carb is a PZ19 Kliene(not sure of the spelling) I have had 2 brand new carbs on it and it has the same problem. Idle's great but when you throttle up fast it dies,,low end rpms are boggy. High rpms are fine once you get there. All intake bolts are tight. Needle changes up or down only worsen the problem. Air flow is unresticted. This engine is brand new. It does have a small paper fule fiter but as I said High rpm is good and its new. I am lost as to what to check. Float? adjustment? The plug is new ,same as the Trail 50 uses.The engine is a Zongshen E22 50cc.

Thanks


Answer
Check the ignition timing....  I imagine that it has some kind of CDI ignition that has a spark module which controls the igntion timing related to rpms.

Unless they are producing defective carbs, the problem is probably elsewhere. Recheck the valve adjustment, while you are at it. They tend to close down quickly on new motors.

Part throttle carb issues are controlled by the slide cutaway and the needle position and to some extent the float level, too.

Bill Silver