Part nr. PN26031000
Tuning-cylinder for Vespa VM, VN, VL, VB, Acma, Motovespa, VGL1
This cylinder suits 125-150 cc motors built from 1953 to 1959 which have two transfer ports in the crankcase. The Pinasco cylinder is designed for the 57mm stroke crankshaft of the 150cc models. If the Pinasco cylinder should be used on a 125cc engine, the original 54mm stroke crankshaft has to be replaced by the 150cc type crankshaft. Since the power is almost doubled we always recommend to use a new crankshaft (Stoffis, Pinasco etc., as shown below).
A perfect carburetor choice is the Polini CP19 if you like to keep the original intake manifold. If you are heading for more power you have to use the intake manifold 3331742 in combination with a Polini CP23 carburetor.
material barrel: aluminium
cylinder head with 5 bolts
2 chromed piston rings
PLEASE NOTE: It's necessary to use a 57mm crankshaft! (please see below)
In the download area below you can see a diagram of the cylinder using prototype exhaust BGM BigBox Touring as well as CP23 carburetor which shows a torque of 14,6Nm at only 3600 rpm and a fantastic power of 10,4 hp at 6100 rpm.
Please note: Since the crankcases of the models VM/VN1/ACMA/Motovespa are very often not sufficiently machined, it's necessary to reduce the length of the piston skirt by 0,5 - 1 mm.