The return of the prodigal PK flywheel! PIAGGIO decided to end the production of these sorely missed components many years ago. Since then this type of flywheel was only available from the PL170 stocks or, in an emergency, as heavily-modified PX items. We have been trying to get a version in production for quite a while as the process was complicated by the limited production run and the requirement for completely new castings. Now, finally, we have them in stock and available!
The SIP PK Flywheels are identical to the original PIAGGIO items in both form and function. Their total weight of 1850gr provides a noticeably improved throttle response at low revs combined with a smoother running motor at mid and high revs. Each flywheel is individually tested and balanced before it leaves the factory.
The PK flywheel with 19/20mm oil seal/bearing seat diameters are part of the simplest method of upgrading Vespa V50/PV/ET-3 models to an electronic ignition system. The addition of a suitable stator-plate, electronic regulator, ignition coil and wiring loom adapter completes the conversion with the existing crankshaft! They also provide a useful update for all series I Vespa PK 50-125 models.
For tuned motor set ups we recommend the 20/20-24/25mm shaft-stub sizes that was PIAGGIO original on the series II Vespa PK 50-125/S and the XL/XL2 models. The thicker stubbed crankshaft type is also necessary for the 12V ignition conversion and is also tough enough to handle the extra power. The second woodruff-key slot makes it suitable for use with PX motors, as well as converting series 1 PX models to an electronic 12V ignition. The origins of this component also lie in the PX range. Its lightweight design provides the largeframe motors with an improved throttle response and ample power for smooth acceleration while changing up through the gears.
Conclusion : A flywheel of this type is most effective plug&play add-on for a noticeably improved acceleration and throttle response, instantly! It also provides the scooter with an improved ignition spark and provides the basis for a 12V lighting system, especially useful while riding at night.
SIP - TIP : The SIP Road exhaust, a touring cylinder such as a MALOSSI 210 or the D.R. 177 complete the set up ideally. Do not forget to order a suitable stator-plate, electronic regulator and an ignition coil for the complete 12V conversion!