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Polini engine case with diaphragm intake, compatible with your Vespa P 125X, PX 125 Lusso, PX 125 MY, P 150X, and PX 150 MY scooters.
The completely redesigned housing is designed to replace the original Piaggio engine housing and remains compatible with original Vespa components. Instead of the classic rotary valve intake, this engine block uses a flat diaphragm system. This helps resolve issues caused by worn intake sealing surfaces and allows for the installation of a racing diaphragm block with a 28/30 mm carburetor. The standard SI carburetor can still be mounted on the housing, including the version with separate lubrication.
The housing halves are numbered in pairs and machined together to ensure that bearings and sealing surfaces fit together perfectly. The flow path of the crankcase and overflow ports has been optimized using CFD simulation. The swingarm, the gearbox area, the shock absorber mount, and the cylinder base are reinforced, creating a stable foundation for powerful street engines as well as racing setups.
On the clutch side, a ground steel flange supports the bearing; this design also prevents the shaft seal (colloquially known as a Simmerring) from migrating. On the ignition side, a larger bearing measuring 25x52x15 mm is used. M8 hex screws replace the classic M7 through-bolts and make the housing assembly stiffer. The motor housing is made of heat-treated Al Si10 Mg T6 aluminum alloy and is designed for an electric starter. The offset gearbox oil filler neck increases the oil capacity and improves lubrication within the gearbox.
The silent blocks are pre-installed; the package includes both housing halves as well as all small parts required for installation. The shaft seals and bearings are also included.
You can find the matching clutch cover and cylinders in the accessories section.
Quality product from the Italian manufacturer Polini.
| Manufacturer | Polini |
| Material | Cast aluminum |
| Width | 320 mm |
| Height | 345 mm |
| Ignition type | Electronic |
| Total length | 420 mm |
| Vespa | Vespa PX, T5, Cosa - P125X · VNX1T · 1977 - 1982 (PX alt) Aussenverschluss , P125X · VNX2T · 1981 - 1984 (PX alt) Innenverschluss , PX125 E · VNX2T · 1982 - 1993 / Lusso / Arcobaleno , PX125 · VNX2T · 1993 - 1996 Classic , PX125 · VNX2T · 1997 - 1999 (Disc) , PX125 · ZAPM471 · 2001 MY Katalysator (Millenium) , P150X · VLX1T · 1978 - 1993 , PX150 · ZAPM742 · 2001 MY Katalysator (Millenium) |
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