General Specification - VESPA 90 Operation And Maintenance

GENERAL SPECIFICATION
Installation of engine (see fig. 12): The
engine is pivoted to the chassis of the vehicle
through the crankcase swinging arm (clutch
side). The rear wheel is fitted on the outer
side of the main shaft.
Lubrication of engine (piston, cylinder,
crankshaft, main bearing
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flywheel side)
is effected by the oil in the fuel mixture.
The clutch, the main bearing
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clutch side,
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and gear box function in an oil bath.
Fuel supply (see fig. 8): gravity feed with
mixture of oil and petrol. Carburettor pro-
vided with a throttle slide.
Three way tap ("closed", "open", "re-
serve ").
Clutch (see fig. 3): multiplate on the lay-
shaft. The unit is operated by lever located
on L.H. handlebars and adjustable cable.
Gear box (see fig. 7): three speed drive
with constant mesh gears. Operated by the
twist grip on L.H. handlebar which functions
in conjunction with the clutch control lever.
Transmission ratio engine to driving wheel:
Bottom gear I : 17.18
2nd gear I: 9.66
3rd gear I: 6.12
Starting (see fig. 6): by means of a kick-
starter on the R.H. side of the vehicle.
Cooling: at all speeds by means of a cen-
trifugal fan.
Air intake: situated inside the frame.
Exhaust silencer: combined expansion and
absorption type.
Chassis (see fig. I): of pressed sheet stee
with streamlined monocoque type structure,
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