Crankshaft -BGM ORIGINAL standard (rotary valve), 51mm stroke, 97mm connecting rod, cone Ø20mm- Conversion shaft to 125cc (PK50XL/XL2) and electronic 12V ignition (V50, 50N, PV, ET3, PK50S, PK80S, PK125S)

BGM Pro hybrid crankshaft with 125cc stroke and PK50XL cone for V50, PV, ET3, PK50

• The PK125S still has the small crankshaft type with the small, pointed 19 mm cone of the Primavera and ET3 models.
• The PK125ETS and PK125XL2 have a larger bearing seat (25 mm) both on the shaft and in the crankcase than all other smallframe models. The cone, on the other hand, is identical to that of the PK50XL / XL2 models. If you want to install such a 125cc ETS shaft in a V50 or PK50, you have to use a special conversion bearing and shaft seal ring due to the large bearing and shaft seal ring diameter.

So that this effort is not necessary, we have a crankshaft type that was never built by Vespa itself. A hybrid shaft from the long stroke of the 125cc vehicles in combination with the bearing seat and cone of the PK50XL models. The shaft offered here therefore fits all V50, Primavera, ET3 and PK50 engine cases! This means you can use the usual bearings and shaft seals, but still have the stable bearing seat and large cone available for converting to electronic ignition

. Attention: Shaft does NOT fit in PK125ETS or PK125XL2 engine cases!


Material:
The BGM crankshafts are forged like in the good old Piaggio days. During forging, the material is pressed together under high temperature and pressure. This results in a higher density of the material. Heat is dissipated much better. The material is more resistant to warping. This is a huge advantage over the crankshafts produced by other manufacturers, whose materials often do not even reach the level of a standard shaft.


Tuning:
The high quality of the material used also allows the use of very light pole wheels without the risk of crankshaft damage. As a result, better acceleration behavior can be combined with significantly increased engine durability. This is particularly important on high-displacement and high-speed engines.


Improvements:
An interesting side effect is the conversion to an electronic 12V ignition, which is always necessary when converting a Vespa 50 or Primavera 125 to this type of crankshaft. With our BGM ignition kit, even the otherwise badly underexposed 6V Vespas can enjoy the benefits of bright halogen light.

Control angle:
The control angle of this crankshaft corresponds to that of a standard 125cc shaft. This makes it equally suitable for the construction of a standard 125cc engine as well as a solid 133cc street tuning. The precise manufacturing, the material used and the good bearings enable many tens of thousands of kilometers of trouble-free mileage.

For higher performance requirements, we also offer the same shaft as a racing version with an extended intake control angle.

• Stroke: 51 mm
• Connecting rod length: 97 mm
• Control angle: Standard
• Cone type: PK XL50
• Conversion of ignition/pole wheel necessary: Yes
• Bearing seat: 20 mm (6204 ball bearing and 20 mm oil seal)