Polini 208

Large frame vespas aren’t my thing, but interested to know if anyone has had any positive results with this kit (correctly timed and carb set properly) . I’ve heard the old adage about „I blew one up in the 80’s“ but we used to plug and play the kits back then didn’t we ?

Heard this kit is good for 17bhp and it seems competitively priced

You are right Curare. Its very frustrating. I found the same thing with the head. They do need a big squish clearance. I think the differences you are finding is that most British scooterists want high speed motorway bikes and this is where most of the problems seem to occur. Theres nothing like a 300km journey of constant motorway to kill a polini!

Try this.

Its a shame because the polini kit is really what most p2 owners want. If malossi had made it it would be brilliant. Still cant understand why they didnt just copy the port timings and made it with an alloy barrel and a decent piston. Saying that the new piston is better we’ll just have to see whether its better enough!

Trouble with the new piston is it still only uses one ring. This is rubbish. Just set a polini up. You must use a large piston to bore clearance( at least 5") a low comp head and timing at about 16 to 17 degrees. Used a main jet on a p2 carb of 145

not too good overall then considering the gs piston is about £60.

thanks guys

hello Avenger,

yes I have got positves results with this kit in very standard conditions, just bolt on with a Simo pipe and a 122 jet on a 24/24, (much, much better then Malossi just bolt on with no other mod. ) up to more complex set up with special lip long stroke crank and reed block.
I personally never had major problem with one of this kit if properly fit and timed, but considering the reports from competent people I know, it seams that one on ten can give you problems, in the same way Mazzucchelli race crank can one in a ten.

I found this kit to be very sensitive to the head you are using so try, if you can, two of them of different shapes.
For example in a longstroke version the use of a Worb5 head made for longstroke with a squish of 2,5mm (to use with no head gasket) the difference with a MMW head with the head gasket was as noticeble as going from standard stroke to longstroke.
And I agree with Diablo. I would love one of this made as it should have since the beggining. If I had money I would order a special production in alu from gilardoni with a special piston…

maybe SIP one day could order a Polini 208 Special edition…
I think they would sell them all even at double price the actual kit is.

The new Grand Sport piston it seams just half way through the right path.