Inclined twin cylinder piston-port 2-stroke, water cooled with oil pump lubrication.
Bore Stroke 76mm x 72mm
B.H.P. at RPM 48 @ 6,000
Max Torque 45 ft lb @ 3,000 rpm
Carburettor 34mm mk1 36mm mk2 early 38mm mk2 with the later porting
Lubrication Silk duplex micrometering pump fed from seperate oil tank.
Fuel Air ratio 50:1 approx
with centrifugal advance and retard.
Twin 6v coils in series.
Ignition Timing Mk1 7mm BTDC Mk2 5mm BTDC
Late Mk2 7.6mm BTDC
Spark Plugs NGK B8HS
Exhaust Siamese Expansion Type.
Primary Renolds Dupex 0.437 roller chain
Clutch 6 plate running in oil mist, Or 7 plate Triumph conversion
Gearbox Four Speed
Final Drive Renolds 5/8" x 1/4 roller chain Rear Sprocket 36 Teeth
Front Sprocket 17 Teeth Alternate 15 or 16 Teeth