polini 177


this is to share experiences.

Last month I finished another PX engine that I have been using daily since then.

I was not sure of the result since contradictory experience on this board.
I am using Polini 177, ported engine cases, malossi reed, 30 Mikuni, RZ right exaust, plug bosh 3 AC, ignition 17, longstroke Worb 5 special lip cranckshaft, 1,5mm head gasket (tried base gasket, with Polini better head one), and 21 Cosa clutch gear, renforced clutch springs, renforced clutch with outside ring welded.

Vibrations less then advanced Mazzucchelli 57mm
Start half pedal kick
3000km voyage 90 - 100 kmh cruising speed 0 problems.

I’m using the electick start flyweel, needed to cut some metal out of the cylinder base to fit.
For the city I will put back the Pk flyweel.

Some people lamented problems with polini kit in a much less tuned configuration !!!

And a question: did somebody tried the HP4 flyweel and what do you think about. Thank you.

[:roll:] [:roll:] [:roll:]

I have it on my race engine. The engine respons very well but it gets really hot and it´s to light, I would not use it on my other scooters.
I would go for the electick start flyweel, I have used the PK XL flywheel from SIP on my PX210 but it did not work out the way I wanted.

Best regards

Patrik Grann


thank you for your answer.