Frame

Numbered 24376 to 30939 (approx). Bolt on seat stays with drawback type chainstays for rear wheel adjustment.

Wheels

WM1x21 (f), WM1x21 (r). interchangeable with black enamelled rims. Black spokes with NPB nipples. Rear with separate rear sprocket carrier assembly. (dogged drive).

Mudguards

5” D section, unvalanced, front and rear. Rear with detachable tail section.

Tanks

Petrol/oil tank black with gold lined panels. Twin screw or Westwood type fillers (Screw thread fillers - external thread for welded tanks, internal coarse thread for soldered tanks) with front fitted petrol balance pipe. Single bolt damper arm fixing. Brass lever petrol tap.

Engine

Numbered 46000 to 52000 (approx) - Tuned (higher compression options) 4 valve 499cc with cast iron open valve cylinder head, parallel inlet valves and parallel exhaust with enlarged inlet port. Splayed exhaust ports.18mm side plug. Rockers supported on plates bolted to the cylinder head. Forward mounted ML Maglita or round ML magneto. Square based cylinder barrel and plain drive side crankcase. Total loss oiling with vertical adjustable ‘pump’ in timing cover.

Brakes

8” x 1 1/2” front and rear, coupled with steel shoes.

Electrics (optional)

Miller 6” 64E headlamp with rear switch and 34E rear lamp.

Transmission

4 speed semi-close ratio gearbox with hand change on RHS of tank. Gearbox with external kickstarter stop. Steel primary chain cover and ‘angle iron’ type chainguard.

Carburetter

Amac type 10MDY with Amac 2 lever or optional twist grip control

Exhaust system

Twin 1 3/4” low-level downpipes into Rudge ‘can’ type silencers and 6” fishtails. Pipes swaged down to 1.5" to fit the cylinder head ports.

Standard Fittings

1” non adjustable handlebars with folded type inverted levers and André steering damper. André lever type fork damper. Single toolbox fitted behind the rear frame tube across the machine. Rear stand. Closed ended ‘D’ section forks.

Extras

Rear brake lock for use when a sidecar is fitted. Rear carrier (at no extra charge).

©  Colin Chapple