Polini..which piston ?

[mick1]

Decided to build a p2 lump out of casings and bits and bobs i've got in the garage. I've got a 207-209 ? polini barrel with a 1 ring piston (barrel and piston original, never used). Not sure if this is the best piston on the market so was wondering what a decent alternative would be...answers much appreciated..

[gaz_powell]

you would be better using a two piston there are two availble - a genuine one from polini and SIP do their own GS - i think both are asso

http://www.sip-scootershop.com/en/produ ... a+_2040920

http://www.sip-scootershop.com/en/produ ... +_12034000

other alternative is a malossi 210

i was thinking about this recently and wondered what scope there would be to modify a standard piston to use in a polini/mdp- there are some reasonable over sizes out there now with thin rings for not much money 67.5, 68 and 70mm

[mick1]

Just looked at SIP site (i must have a 208) the GS seems a good choice

[gaz_powell]

http://www.sip-scootershop.com/en/produ ... a+_2040920 £64.00

http://www.sip-scootershop.com/en/produ ... +_12034000 £87.00

i think i would go with the genuine polini - its the piston that comes with the kit now

the sip piston came out when polini only offered a single ring - not long after polini changed to 2 ring

[Spanish Fly]

I've also been considering this dilemma.
The GS is my preferred option it has 1.0mm rings which allows the possibility of running a wide exhaust port.
It also 'looks' much stronger than the Polini. Those huge side windows and minimal suuport for the gudgeon pin boss in the Polini piston just look wrong to me.
I did have a look at the Malossi piston which is a tough as old boots but would need either, additional windows cutting or the existing windows being radically enlarged. I figured that would make it weaker and having bits of piston fall off isn't the plan.

SF