Cylinder -PARMAKIT TSV66 ‘sixty six’ 205ccm, 110mm con-rod, Ø16mm piston pin, 60mm stroke, 3 Ports- Vespa PX125, PX150, Cosa125, Cosa150, LML Star 125/150, Stella 125/150 online ora

The Parmakit TSV66 series offers by far the largest displacement available on the Vespa PX 80, PX125, PX150 and LML 125-150cc engines, with 195cc and 205cc respectively.
The cylinders require the crankshaft of the PX200 models.

The crankshaft has the necessary longer connecting rod (110mm instead of 105mm)

The following work is necessary to accommodate the cylinder and crankshaft in the so-called small engine block:

engine housing
1. Spindle out the cylinder base mount for the larger cylinder bore.
2. turn out the crankcase width to be able to use the wider rotary valve cheek of the 200’s
or alternatively
3. conversion to intake control via diaphragm

CROWN SHAFT
1. alternatively to step 2 of the engine block machining, the shaft can also be turned narrower at the rotary valve surface (turn off the web). In this case, however, the advantage of a wide rotary vane cut-out and the resulting possible increase in performance is not applicable.

2. Use of a crankshaft for diaphragm control. On the LML motor housings with a diaphragm inlet control already ex works, the use of a solid crankshaft is recommended. The inlet offers sufficient space. All other housings use better a so-called lip shaft, which provides sufficient intake surface by its interrupted cheek profile, without the housing would have to be revised in addition strongly. The use of a solid cheek-shaft in a former rotary vane engine case requires a quite extensive reworking of the inlet section.

The Parmakit TSV66 is designed as a powerful touring cylinder. It therefore offers a lot of torque from the basement with a very good bandwidth. This should be supported by a suitable exhaust system (e.g. BGM Big Box) and a not oversized carburettor cross section (Ø24-30mm).

TIP: If you want to get the maximum out of the cylinder, use the cylinder for 57mm stroke on a crankshaft with 60mm stroke. This allows the cylinder to be placed underneath the foot, which increases the steering angle massively and is therefore suitable for sharper exhaust systems. An appropriate exhaust treatment provides then for the remainder around a rear wheel achievement of 30PS to come closer.

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