Modern Vespa

Hi all. PK 125 S.

A few times after refitting my carb the scoot screams at high revs from start up (I turn it straight off), after fiddling about I can get it running as usual, but I've never realised why. I rebuilt the carb a while ago, but this time it was after cleaning the tank.

It did it again today and while trying to sort it, I nudged and moved the throttle outer, and that would make the revs even higher. So I'm thinking it's the throttle cable caught somewhere and me fiddling about before has accidently sorted it. Once I removed the throttle cable I could get it idling as usual. (Before doing so, even with the idle all the way out it was revving at half throttle or so)

There's loads of cable at the carb which is free, but then feels tight in the tunnel and tight at the headset. I'm planning on trying to free the cable up by pulling and pushing a bit, maybe even changing the cable but I've heard it's a nightmare? Any ideas from anyone?

If it is actually the cable binding I would pull the inner( leaving the outer in place) and replace that first. You will need one of the small pinch bolts for the carb end.