1931 250cc
Frame
Numbered 42996 to 46500 (approx). Bolt on seat stays with drawback type chainstays for rear wheel adjustment.
Wheels
WM1x19 (f), WM1x19 (r). with identical hubs and black enamelled rims. Black spokes with NPB nipples. Bolt on rear sprocket.
Mudguards
Plain inverted U section 5.5” wide, unvalanced front and rear. Rear with detachable tail section. Tail section supported by wire stays.
Tanks
Petrol/oil tank finished in black and gold. Twin Westwood type fillers (oil & petrol) with rear fitted petrol balance pipe. Single bolt damper arm fixing but no damper fitted. Brass lever petrol tap. Oval 'Rudge-Whitworth' rubber gnee grips.
Engine
Numbered 1 to 700 - 4 valve 249cc with cast iron open valve radial cylinder head, bolted to the barrel from below. 18mm central plug. Miller coil ignition with contact breaker mounted in the timing cover. Oil feed to rear of cylinder. Ignition coil mounted across front of crankcase. Rear mounted short DM3 Miller dynamo.
Brakes
Both 6 3/4", coupled with steel shoes.
Electrics
Miller 7” headlamp (bayonet fitting rim) with No 74E or later No 75 6-0-6 'Lighthouse' (illuminated) ammeter and 34E (early models), 39E or 39ER (latest models) rear lamp. Later machines used the No 74ES headlamp with the clip fitting rim. Ignition tell tale mounted on handlebars with ignition rotary switch in headlamp rear. DM3G dynamo and Miller coil.
Transmission
4 speed gearbox with hand change on RHS of tank. Pressed steel primary cover with no inspection holes.
Carburetter
Vertical Amal type 5/142 with 2 lever control.
Exhaust system
Twin 1 3/8” low level pipes into Rudge ‘can’ type silencers (smaller than 500cc version) and 5” fishtails.
Standard Fittings
Non adjustable 1” handlebars with folded type inverted levers. Single toolbox mounted opposite battery carrier on nearside of machine. Pressed steel centre stand. Open ended ‘D’ section forks. No steering damper or fork shock absorber fitted.
Extras
Chromium plated tank with black or maroon panels and black with maroon guards and tank panel. Smith’s trip/non trip speedometer, Bonniksen speedometer, legshields, electric horn, Lucas No 63 bulb horn.