S p e c s: V9SS2T

1971 - 1974
engine: single cylinder, air cooled 2-stroke
induction: disc valve
bore: 47 mm
stroke: 51 mm
cubic capacity: 88.5 cc
bhp at rpm: 5.1 @ 5750
transmission: 4 speed constant mesh
1st gear: 14.74: 1
2nd gear: 9.80: 1
3rd gear: 7.06: 1
3rd gear: 5.31: 1
clutch: wet - multiplate
carburetor: Dell'Orto SHB 16/16
main jet: 82
slow running jet: 38
throttle valve: No 2
starter jet: 50
ignition: contact breaker & coil
ignition timing: 24 deg. BTDC *
breaker gap: 0.3 - 0.5 mm
voltage: 6 volt
click for the V9SS2T electrical page

*Note: The Haynes manual shows the timing to be 24 degrees BTDC but I was under the impression that this is the same engine as the 90SS (which shows 19 degrees BTDC) just in a different body. The compression ratio on the Racer is also not noted which makes it possible that the Racer head is different. The GS150 had a head change in the last years of production which changed its timing by 4 degrees - If anyone knows if this is the case please email me. Thanks to Stefan Peterssen - Vespa-Club Bremen e. V. / Germany for the pictures.