Vespa PX125 150 LML Sprint Cosa Malossi Sport Racing Alloy 3 Port 187cc Cylinder Kit

Malossi has extended its range of cylinders for the Vespa largeframe engines with 125-150ccm (Sprint, PX, Cosa, LML) by the three cylinder versions Sport 177ccm, MHR 177ccm and MHR 187ccm.

They are completely new designed and have nothing to do with their predecessor made of grey cast iron and only 166ccm. The aluminium used as cylinder material makes the kit thermally more stable than the 166cc cylinder and now allows a Ø63mm bore. Externally the cylinders are almost identical. All three versions use the same cylinder head and the same piston (but the piston of the sports cylinder has two piston rings). The formerly patented CVF II system has been dispensed with, instead the overflow channels have been significantly enlarged. An adaptation to the engine housing is therefore mandatory for full power/torque.

MALOSSI 187 MHR60
The MHR cylinder range is aimed at the advanced tuner who wants to get the maximum out of his engine. A corresponding knowledge of the complex thermodynamic and mechanical processes in the engine is tacitly assumed here. A nice feature is the screw-on exhaust flange. This allows a further reworking of the exhaust port, which can greatly increase the performance of the cylinder. Malossi states the achievable power at delivery with 22-30PS. For the use of the cylinder a crankshaft with 60mm stroke is necessary.

• HubxBore: 60xØ63mm
• Hub capacity: 186,94cm³
• Exhaust angle: 178,5°
• Overflow angle: 122,5°
• Forward exhaust angle: 28°
• Squish edge: 0.8mm (piston is back by 0.3mm at top dead center)
• compression: 1:11
• overflow channels: 7
• piston rings: 1
• ignition point: 18°v.Ot.

A major revision of the original rotary vane inlet is recommended, better in terms of maximum performance and driveability is the conversion to a diaphragm controlled inlet. The BGM BigBox Sport or the RR-Box is a good choice as exhaust. Both support the cylinder very well in the intended speed range and thus enable the full potential of the cylinder to be exploited within the framework of an unobtrusive but fast engine concept.