thumpstar problems

[kellett1234]

I have a thumpstar 150cc lifan engine , having trouble with it can anybody help . starts fine , idles good , and when u start riding it starts jerking , it has a new spark plug , ive stripped the carbie down and cleaned it , its still doing the same thing , the carbie is a 26mm oko.
thanks

 

[sean01]

has the carb always been on there?

if so then take a look at your cdi unit.. if it has an inner rotor kit than ya can bet thats your issue..

also confirm your jets sizes and needle position..

 

[lenny17]

Look at any connecting wire near or under the seat. Make sure they are not lose And nice And tight.

This happen to me And as soon as I sat on the bike my seat would rub against the joining part of 2 wires forcing them apart and shorting out..

 

[lenny17]

Look at any connecting wire near or under the seat. Make sure they are not lose And nice And tight.

This happen to me And as soon as I sat on the bike my seat would rub against the joining part of 2 wires forcing them apart and shorting out..