I have a Baja 90cc wilderness quad. The vehicle runs fine after it warms up for 15 minutes, I timed this. Before 15 minutes you push the throttle and it will not rev up just sputters and won't go anywhere. I cleaned the carburetor and checked the manual choke and all appear to be in working order. The spark plug was replaced and it has fresh gas in it. After it warms up for the 15 minutes it runs fine. I don't know what else to check. Maybe a module. Any advice or opinions would be greatly appreciated. Thank you JeffV.

 

Welcome to the forum Jeffv!

Your quad is jetted lean (all 4 strokes come this way to pass EPA/CARB tests). this lean condition makes for a long warm up time, among other things..

I have larger main and pilot jets in everyone of my Chinese and Honda 4 strokes.