Polini tuning kit for Vespa GTS/GTV 300cc maxi scooters. Included in the kit is piston, camshaft, valve springs & ECU module.

The new piston design increase compression ratio from 10.8:1 to 12.1:1. The camshaft has been designed with a new contour that increases the intake lift from 7.3 to 8.4mm while the exhaust lift increases from 6.9 to 8.1mm. All this helps to improve overall all power and higher rpm power. The kit also comes with valve springs to reduce valve flatter. The ECU module controls the increase in fuel flow the cylinder will require with the new parts.

The ECU supplied with the kit has 4 maps installed:
1 – scooter equipped with powered piston+cam+Polini Variator+original muffler -
2 – scooter equipped with powered piston+cam+Polini Variator+Polini muffler -
3 – scooter equipped with powered piston+cam+Polini Variator+Racing muffler -
4 – original scooter+Polini variator+Polini muffler

When doing any tuning work it's always worth running it on a dyno to check for any possible set up issues. The ECU also has the option to manually decrease or increase the fuelling which would be advisable to use a dyno for.

*Piston diameter = 75mm.

Polini 140.0217