2003 PX125 Disc chronic misfire at speed

[Pompeydave]

Hi all, very late update I realise, but just to let everyone know that after all the electrical work I've done the problem did indeed turn out to be a faulty fuel tap- the flow was far too little. As soon as I put the SIP fastflow one on the problem cleared. Thanks for all the advice along the way .

[fraserp200e]

Sorry to ressurect this thread but I've got a very similar problem.

Only when the throttles held fully open so at the top end of the revs (mainly in 4th but sometimes in 3rd), it just seems to misfire and hold back as if the brakes is being dabbed very quickly. Sometimes when riding fast for long periods it just dies as if it's run out of fuel, clutch in and it bumpstarts as you roll to a stop and then rides fine for a while before I get the same sysmtoms.

I thought it was fuel related so checked the carb / jets, fitted a new BGM fast flow tap, new reinforced fuel line and cosa float bowl but that didn't solve the problem. It does seem to be worse when the fuel level is low though.

Looks like I need to check the stator and CDI from the previous comments........

[fraserp200e]

Changed the stator and no change, fitted a new carb and all sorted, I was sure it was fuel related.