S p e c s: VSC1M motor

1964-1968
casing mouth: 2 transfer ports
induction: piston ported
bore: 62 mm
stroke: 60 mm
cubic capacity: 181.15 cc
compression ration: 7.7: 1
bhp at rpm: 8.7 @ 5750
con rod length: 110 mm
piston compression height: unknown
piston type: domed
small end diameter:unknown
big end diameter:unknown

flywheel side bearing: 25x52x15
drive side bearing: 25x62x12
input shaft bearing: 12x37x17
output shaft bearing (flywheel side): Piaggio only
rear wheel bearing: 20x52x15

flywheel side inner oil seal: 52x32x5
flywheel side outer oil seal: 24.9x45x6.5
drive side oil seal: unknown
rear hub oil seal: 30x40x7
 
SS180 LINKS:
Electrical Diagrams
Parts Book
Owner Manual
 

Casings: The casings are only shared between the SS180 and the GS160 models although they look similar to other casings.

Bearings: Most bearings are easy to come by with the exception being the Piaggio specific output shaft on the flywheel side. This bearing is located just inside the selector box and is specific to the GS160 and SS180.

Cranks: The crank is specific to the GS160.

Standard barrel: The standard VSB1M barrel is a two port design with a piston ported intake. The SS180 barrel and piston is the only option for a larger capacity.

Kits: Unfortunately there are not really any options except for the SS180 conversion noted above.

Ignition: The original 6V points system cannot be replaced without significant work to the flywheel of another model.

Gearbox: Unknown if any other gearboxes can be installed but I assume the SS180 could be.