High quality crankshaft for the Motovespa GT160 engines

Motovespa GT 160

The Spanish licensee Motovespa SA based in Madrid has developed the Motovespa 160 (09C).

Definitely an odd specimen - electronic ignition similar to the Serveta Lambrettas but still with piston connections. The body is basically a sprint/rally, but the engine is an odd mix of old and new technology.

The Motovespa 160 is often confused with the Super Sport 180, but at second glance you can see the many differences.

Finally, the Vespa 160 GT was a version with a series of side panels and accessories that made it even more attractive.

Exploded views here


BGM Pro crankshaft

The BGM Pro crankshaft for the GT160 is available in different versions.

In general, the original Femsatronic ignition of the GT160 fits all versions. On the drive side there are variants for the original GT160 clutch or the variant to use the PX clutch type.

All PX 6 and 7 spring clutches as well as all Cosa and bgm Superstrong clutches can be used here.

The thrust washer is also used on crankshafts with type PX coupling stub BGM6033 and the woodruff key 9999002 thats it!

We offer both variants with the standard stroke of 57mm and as a long-stroke version with a stroke of 60mm.

For the crankshafts with 60mm stroke, the engine case has to be modified to create space for the lower connecting rod eye.

Since only a small amount of material has to be removed here with a radius of 0.8 to 1mm, this task can easily be completed in a few minutes with a hand milling cutter.

With the 60mm stroke variant, the control angle of the cylinder changes.

Typical for the GT160 cylinder are the relatively large control angles for the transfer ports in connection with the very short control angle of the exhaust port.

With the original 57mm stroke, the cylinder has the following control angles:

Piston recess 0.5mm

Inlet angle: 131°

Outlet angle: 144 °

Transfer angle: 119°

Forward outlet: 12,5°

If the same cylinder with 60mm stroke is used, the following control angles result:

Piston protrusion: 1mm

Inlet angle: 132°

Outlet angle: 148 °

Transfer angle: 124°

Forward outlet: 12°