ENGINE
| Viper. | Venom and MSS. | |
| Bore | 72 mm. 2.8347-in. | 86 mm. 3.385-in. |
| Stroke | 86 mm. 3.385-in. | 86 mm. 3.385-in. |
| Capacity(swept vol.) | 349 c.c. 21.29 c. in. | 499 c.c. 30.45 c. in. |
| Rated Horse-power (A.C.U. Rating) | 3.5 | 5 |
| †Running tappet clearances: | .005-in. | .005 -in. |
Engine serial number and prefix stamped on left hand side of crankcase just below cylinder base flange. See page 34.
GEARBOXES
Overall ratios with standard driving sprocket on gearbox : *
| Viper | Venom | MSS | |
| 1st | 12.6 to 1 | 11.2 to 1 | 12.4 to 1 |
| 2nd | 8.73 to 1 | 7.74 to 1 | 8.57 to 1 |
| 3rd | 6.64 to 1 | 5.88 to 1 | 6.52 to 1 |
| Top | 5.5 to 1 | 4.87 to 1 | 4.87 to 1 |
Gearbox serial prefix and number stamped on top of housing on right hand side.
TANK CAPACITIES
| Fuel | 3 Imperial Gallons; 13.6 litres; or 3.6 U.S. Gallons |
| Oil | ½ Imperial Gallon; 2.27 litres; or 0.6 U.S. Gallons |
TRANSMISSION
| Viper | Venom and MSS | |
| Engine Sprocket | 21T | 23T |
| Clutch Sprocket | 44T | 44T |
| Gearbox Sprocket | 21T | 18T* |
| Rear Wheel Sprocket | 55T | 46T |
| Primary Chain | .5 x .305-in. 67 P Roller dia. .335-in. |
.5 x .305-in. 68 P * Roller dia. .335-in. |
| Rear Chain | .5 x .305-in. 124 P Roller dia. .335-in. |
.625 x 380-in. 101 P Roller dia. .335-in. |
WHEELS & TYRES
| Viper | Venom | MSS | |
| Front Rim | WM2 x 19 | WM2 x 19 | WM2 x 19 |
| Rear Rim | WM2 x 19 | WM2 x 19 | WM2 x 19 |
| Front Tyre | 3.25 x 19-in Rib | 3.25 x 19-in Rib | 3.25 x 19-in Stud |
| Rear Tyre | 3.25 x 19-in Stud | 3.25 x 19-in Stud | 3.25 x 19-in Stud |
FRAME
Serial number and prefix stamped on right-hand side of front seat lug
†These are running clearance set cold. Different clearances must be employed for checking valve timing. See page 40 before checking or adjusting.
Always quote the engine serial number and prefix on all orders for spare parts and in any correspondence with the factory.
*A smaller sprocket and shorter chain are used if a sidecar is fitted.