Modern Vespa

Hello all! I'm new to all this and to building vespa's so here goes! I have a 1984 PX 125 e vespa and I have had an oil leak and a compression problem with it so I'm rebuilding the engine! I've taken the cylinder head off and as suspected there's lots of oil and crap there more than normal! I know the piston rings are normally 52.5m for my bike but there is no number on the top of the piston. Also on the under side of the head there is a number which is 150 s 990176 6a this is confusing me! Is a 150cc head? Would that fit a 125cc? Could the engine be a 150cc? Any help from you guys will be massively appreciated!! Thanks!

A 150 head will fit on a 125 with the correct piston and barrel this is not an unusual upgrade, I think the 125 would be stamped 125 both the ones I have worked on were. BORE - P125X 52.5mm, P150X 57.8mm

Ricky

Thanks For the help Ricky!

Hello again! So I'm thinking of putting a kit on my vespa either a 166 malossi or a 177 polini which kit would be the best? now these are both full cylinder piston and all that but what else would I need? I'm looking at a new exhaust but would I need a new carb or air filter? Any advise would be extremely helpful!
Take care

Fast answer - Malossi for max power at the top end, Polini for less top end but good broad power addition. Yes you can add a good exhaust, check out the SIP Road. You'll want at minimum a 20/20 carb or better a 24/24 with proper up jetting* and the bigger filter.


*For technical advice & discussion, you ought to post up over in the Not So Modern section. But first read thru several threads that look relative to your topic and you may find what you need.

Thanks matey!