Vespa Kits

Vespa Small Frame - Malossi 133

Click here for a .pdf version of Malossi's instruction manual.

Malossi's installation instructions (above) are pretty goofy but a good place to start. Here are the basic specs:

Timing 17 degrees BTDC
Bore 57.5mm
Stoke 51mm (standard)
Compression 11.4:1
Capacity 132cc
Main Jet 90 (SHB 20/20)

This kit is pretty unique as it can be used with normal crank induction, or the crankcase hole can be blocked up and a separate reed valve induction hole in the barrel can be used. Thanks to First Kick Scooters for the pictures.

The shot above shows the gasket face with the enlarged opposed transfers. The exhaust port is in the same place as the standard barrel. Just below the ring (which was in the barrel when I took the picture) and above the three small rectangular transfers is the reed valve intake option.

 

The above shot shows the reed valve intake option. This can be blanked off if you want to use the standard crank induction system and is a nice addition to the kit. It is located on the opposite side from the exhaust.


 

Another shot of the reed intake below the three rectangular ports.


 

Check out the port layout. Three main transfers translate into seven barrel ports for extra power.


The piston is also very different than the standard Piaggio item. Windows are also cut in around the ends of the wrist pin which can't be seen in this image.


The head is specific to this kit but could use a bit of polishing inside the combustion chamber before installation. There is no head gasket, but rather a rubberish O-ring that fits in the circular groove.


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