| Frame numbering |
1963 Prefix FM25S - xxx. 1964
Prefix GM25S - xxx etc |
| |
|
| Engine |
Villiers 2T. (1964 on - 4T) Capacity
250cc.
50mm x 63.5mm |
| Gears |
Four speed |
| Frame |
Single downtube with swinging-arm rear. |
| Forks |
Telescopic |
| Tyres |
1963: 3.25" x 18" front & rear.
1964 on: 2.75" x 19" front. 3.25" x 18" rear |
| Tyre pressures |
|
| Wheel rims |
Dunlop WM2 36 hole |
| Ignition timing |
2T: 3/16" btdc. 4T: 5/32"
btdc |
| Points gap |
0.012" - 0.015" |
| Plug gap |
0.018" - 0.025" |
| Plug type |
Original spec. Lodge HH14 |
| Carburettor |
2T: Villiers S22 / 2.
4T: Villiers S25 / 2 |
| Jet size |
|
| Needle |
|
| Needle setting |
|
| Tank capacity |
2¾ gallons approximately. Use of unleaded
fuel will cause no problems |
| Petroil mixture |
20:1 as originally specified. Can be
safely reduced to 24:1 with modern oils. |
| Gearbox capacity |
Fill to dipstick level. SAE 30 |
| Chaincase capacity |
Fill to level plug. |
| Chains |
Primary chain: 60 pitches.
Renold 110038
Final drive chain: |
| Sprockets |
Engine: (crankshaft) 20 teeth
Gearbox (final drive) 18 teeth ½" pitch |
| Brakes |
1963: 6" front & 5" rear.
1964 on: 6" front * rear |
Bulbs
Taken from Villiers parts list |
Main bulb: 6v - 30 / 24w pre focus
Tail lamp: 6v - 3w
Stop light bulb: 6v - 18w
Parking lamp bulb: 6v - 3w
Speedo: 6v - 1.8w |
