Throttle problem - Seems to be quite jumpy! Help please

[boeing747]

Hi there,

I have had my pocket bike for about 3 weeks now, and its been going great. But quite recently the throttle has become quite jumpy! Its when I start getting at about 30kph or more, its like the throttle cuts owt and on again very abruptly! Its one of the cheap chinese bikes, wondering whether anybody has had this problem, and how I could fix it? Just another quick problem, the bike seems to vibrate very unusualy at high speeds, and I know it vibrates at high speeds, but this is very unusual, like the chain is hitting something?? Any help would be much appreciated!

Thanks :)

[Pedrostt500]

Ok try cleaning the carb out, check the jets are clear, also check that the fuel tank is breathing properly.

as to the vibrations check that the chain is alighned properly, you may neeed to use washers as spacers to alighn the rear sprocket, some of these can be out of alighnment by quite a bit.
it used to take me a few hours to set these bikes up from new out of the box, Im glad I dont have to do that any more.