S p e c s: VBA1M Motor

1958 - 1960
casing mouth: 2 transfer ports
induction: disc valve
bore: 57 mm
stroke: 57 mm
cubic capacity: 145.5 cc
compression ratio: 6.5: 1
bhp at rpm: 5.5 @ 5500
con rod length:unknown
piston compression height: unknown
piston type: deflector
small end diameter:unknown
big end diameter:unknown

flywheel side bearing: 25x62x12
drive side bearing: 25x62x12
input shaft bearing: 12x40x12
output shaft bearing (flywheel side): Piaggio only
rear wheel bearing: 20x47x14

flywheel side oil seal: 20x40x6
drive side oil seal: 20x62x6.5
rear hub oil seal: 37x27x7

Vespa VBA 150 Links:
VBA1T overview
VBA1T electrical page
Engine Work

Casings: The casings are similar to most 150cc large frame casings with small differences.

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 shared with most other models (except the GS160 & SS180).

Cranks: The same crank is shared on most 60s 150cc including the GL, GT, Sprint, VNB, and VBB.

Standard barrel: The standard VBA barrel is a two port design with a deflector piston. This piston can be changed for a domed type from a later 150cc models but the head will also need to be replaced.

Kits: Unfortunately there are not really any options for a two port 150cc motor.

Ignition: The original 6V points system can be replaced with a 12V electronic ignition kit - the only makers of the kit are ScootRS in Vietnam..

Gearbox: The three speed VBA1M gearbox and the four speed VBB1M or VBB2M gearboxes are interchangeable.