The JASIL 'Standard crankshaft', that are made in Portugal, have the identical appearance, quality and inlet-port timings as the original components produced by PIAGGIO. In addition, they also feature lubrication slots arranged around the big-end bearing and lubrication holes around the small-end making this crankshaft ideal for both standard and lightly tuned motor set-ups.
Originally bell-shaped, full-circle and disc-valve crankshaft types found use on the various Vespa models produced over the years. The earlier models had brass bushes fitted to the crankshafts instead of the, nowadays usual, bearings!
We have sorted the model categories according to the details taken from original PIAGGIO part catalogues. This should make it simpler to order the correctly dimensioned crankshaft for your particular model of Vespa or motor type. We have listed the gudgeon pin diameters, big-end diameters and the con-rod lengths and strokes. Please check these dimensions carefully against the original item before ordering or mounting!
Conclusion : This crankshaft type is ideal as a replacement for the original and is also suitable for lightly tuned motor set-ups.
SIP-TIP : Do not forget to order a new set of bearings, oil seals and woodruff keys! A new gasket set, clutch and flywheel holding nuts are also necessary for a safe and enduring motor set-up. Essential tools facilitating crankshaft mounting and removal include #27338000, #21071000 and #18119000.
The above mentioned inlet port timings are determined by the size and shape of the clutch side crankshaft web, for example - '138°/6° after TDC' means the inlet port opens 6° following the point at which the piston reaches the end of its travel at the top of the cylinder (or Top Dead Centre) and remains open for a total of 138° of crankshaft rotation.
Please note : The degree values are approximate due to the crankshafts being finished by hand.