Hi everyone... first post from me (newbie), so apologies in advance for jumping in with a request for assistance right off the bat!
I've recently acquired a 1999 PX 125 Disc (absolutely love it!), with a Polini 177 cylinder kit and SIP Road 2 exhaust.
It revs cleanly enough and without hesitation, however when the clutch lever is pulled-in to upchange, the engine revs fail to drop-off, only doing so once a higher gear has been selected and the clutch lever released. Reading through various threads on modernvespa.com, it appears that the issue is attributable to either a carburettor or air leak problem.
Taking the carburettor first - there's a very useful SIP guide to carburettor adjustment on the forum which I plan to follow - unless anyone can advise of a better method? I have a Dellorto SI 20.20 with 105 Main and 52-140 Pilot jets to compensate for the cylinder kit and exhaust change.
Secondly, if the issue is down to an air leak, where/what would be the most likely causes for the symptoms described?
Thanks in advance for any assistance/guidance offered.
Riff