Poor performance By onerockscott (Read 478 times)

[onerockscott]

I am at a loss...  

I recently upgrade my GY6 150cc (1P57QMJ) Chinese scooters 8 pole stator to an 11 pole.  The 5 wire rectifier was upgraded to a 6 wire as well as the headlights from dual 18 watt bulbs to 35 watt.

Since I have completed everything, but may be a coincident, my scooter has been running poorly. I can feel it from the moment the scooter starts but is very subtle.  After the complete warm up the sputter is noticeable at acceleration from a stop and is extremely bad/worst at approximately 45mph.

I have tried the following things...

• Tested the stator and believe it to be in working order
• Tested the regulator and believe it to be in working order
• Dissembled and thoroughly cleaned the carburetor.  I saw no obvious signs of malfunction.
• Adjusted the carburetor.  The air mix screw is all the way turned in the clockwise direction.  Turning counterclockwise seriously degrades performance.
• Verified that the gas is good and the problem has persisted through 3 tanks of gas.
• Gas flow seems to be ok
• Airflow seems to be OK with no dirt build up on the filter or other cracks/hole for extra air to make its way into the system.
• Checked the spark plug gap and cleaned a thin layer black suit from it.  This seems to indicate a rich mix.

I am not sure what to try next and would appreciate any sage advice.  I wonder could this be the CDI malfunctioning causing a week spark?


Thanks
Scott

[crwford]

did you recheck valves gaps?

[onerockscott]

Thanks for the suggestion. I hadn't thought of that.

I was able to complete the adjustment and found that the exhaust valve was tight. While there was a slight improvement, the overall problem persists.

Thanks again

[onerockscott]

It seems that the engine was starved for air. In the air box, there were foam pieces that were blocking 2 of the 3 air intake holes. I removed one additional foam piece and all seems to be right with the world.

[cyborg]

Great!!!!! Glad you solved the problem