S p e c s: VNL3M Motor
(P125X)

1977 - 1982
casing mouth: 3 transfer ports
induction: disc valve
bore: 52.5 mm
stroke: 57 mm
cubic capacity: 123.4 cc
compression ratio: 8.2: 1
bhp at rpm: 7.5 @ 5750
con rod length:105mm
piston compression height: 42.5mm
piston type: domed
small end diameter:16mm
big end diameter:20mm

flywheel side bearing:
drive side bearing: 613912
input shaft bearing:6302
output shaft bearing (flywheel side):
rear wheel bearing:6204C4

flywheel side oil seal: 24x35x6
drive side oil seal: 31x62x4.3/5.8
rear hub oil seal: 30x47x6

P125X links:
P125X Electrical Diagrams
P125X scooter page
P125X Parts Book
Casings: The casings are very similar to 150 Sprints.

Cranks: The crank is the same as a later Sprint, and all P series 125 and 150cc bikes which are readily available.

Standard Barrel: The standard barrel has three crankcase transfers. The barrel is not really useful for tuning as there are many aftermarket big bore kits that are better.

Kits: Any 3 port large frame kit over for up to 150cc original bikes.

Ignition: These bikes have 12V points systems but the crank is the correct taper for a P200 electronic flywheel. The flywheel, stator and CDI will need to be used.

Gearbox: Most later large frame gearboxes after the Vespa 150 Sprint will fit. The clutch can be upgraded to a "Cosa" clutch for better performance.