I've got a 2004 peugeot jet force 50cc (injection model). I tried starting it one day and it wouldn't rev then cut out after about 2 mins. To start it again i would need to clean the spark plug but still it wont rev. I've since found a split in the head gasket and replaced that, but still no joy ???
Possibles:blocked exhaust, head gasket incorrect / mating surfaces not perfect (check with steel rule & thinest feeler guague), throttle cable stretched (renew), dirty fuel [clean all lines, tank, renew filter(s)], renew spark plug. Can anything affect the timing? Clean all earths. Start with easiest task. Make checklist.
All the best!
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix motorcycles.