Am looking for a piston to fit my 311 Mont - originals are unobtainable according to Sandifords, does anybody know what other bikes have around a 73.5mm bore size? The barrel needs replating as well so I could get it bored to accept a slightly larger piston then replate or have it sleeved to take a smaller one. The marking on the piston is Gilardoni 2775 i've googled this but all the information seems to come back about Guzzi's

Any help would be appreciated.

Thanks

Giles

Gday, you'll need to know compression height - distance from the pin to the crown, where the ring locating pins are in relation to the centreline of the piston and the dimensions of the pin. After that you need to know whether you can match the skirt design to fit the ports you have. Talk to your local Pro-X aftermarket dealer, they may be able to help you out.

Cheers,

Stork

Here are the dimesions measured with a cheapy pair of calipers - so definately not 100% accurate

Pin 16mm

Overall Height 70mm

Top of pin to top of crown 25mm

Ported in rear of piston & rear of skirt cut away

Distance between ring stops measured directly across the top of the piston is 45mm appear to be centred on the centre of the piston

Will buy a decent measuring set up next.....

Cheers

Have a chat with this company,they know there bit's.

clicky here

Try Kevin Breedon Racing Link If you Email him he will send you a drawing to add your sizes to then have a look for one!