my 110cc motor starts and runs. it used to reach 30-35 mph at top speed. now it only reaches 15mph at top speed. i changed the plug and i still have the same problem what else can i check to solve this problem? What does this problem sound like it could be? Any suggestions?

 

Your carb is dirty..

 

cleaned the carb. and still have the same problem. my engine has 1/2 the horsepower it used to have. please help me solve this problem. thanx.