These lightweight, full-circle racing crankshafts - produced by JASIL - have a polished and profiled con-rod which minimises internal crankcase turbulence. The use of a full-circle webbed crankshaft increases both the density of the fuel charge and the pre-compression ratio. The JASIL 'Evolution NG' crankshaft has been conceived for maximum performance potential and is therefore constructed using extremely durable, high-quality materials. This makes them ideal for use in tuned and ported motors. Contrary to Vespa motor design, Lambretta motors have only two separate crankshaft stub diameters and they are interchangeable. The larger cone stub diameter of 25mm, measured at the base of the oil seal seating, was originally only available with the DL/GP models motor. The smaller stubbed crankshafts measure only 21mm at the base of the oil seal seating. These smaller dimensioned crankshafts are not suitable for use in hard-working and highly tuned motors due to the increased power outputs involved. The old saying that 'bigger is better' certainly applies when tuning Lambretta motors. The thicker the crankshaft stub, the more stability and durability it can offer your tuned motor set-up.
Conclusion: At last! An ideal crankshaft to prolong the effective life of TS 1 kitted Lambretta motors. These crankshafts are equipped with numerous modern features, including holes and slots surrounding the high-end bearings, that noticeably increases the overall longevity and durability of any Lambretta motor.
Full-circle crankshaft / 58mm stroke / 107mm con-rod / 25mm diameter shaft
Full-circle race crankshaft, 107mm con-rod, thick/blunt 25mm shaft, includes small-end bearing, machine forged con-rod with practical lubrication openings surrounding the bearings, forged crankshaft webs, lubrication holes around the small-end bearing, lubrication slots around the big-end bearing, high-end big-end spacers.
SIP-TIP : We strongly recommend the inclusion of a crankshaft with a thicker 25mm diameter stub, originally only included with Lambretta DL/GP models, in high-power tuning set-ups. Do not forget to order a suitably dimensioned crankshaft oil-seal! The conversion to the thicker stubbed crankshaft also allows the introduction of an electronic ignition to your motors set-up.