Norton 850 Mk 1 1974, Service Notes, Page: 5 / 48

THE MOST SIGNIFICANT CHANGES IN THE MANY COMMANDO MODELS
Engine Nos.
126,125 FIRST COMMANDO, 17E(3 'G4. Silver tank, panels and frame-orange (!1 seat. Green blob on tank.
131,180 Now called FASTBACK, Conventional color scheme. Gusset below head-stock replaced by horizontal
bracing tube (under tank). (The first frames broke).
131,257 First "S" type made for American market. Smaller rounded (Roadster type) tank. High level parallel PIPES
left hand side, with reverse cone shape silencers. Points on the end of the cam shaft, REV. counter drive
inboard. Six volt coils with ballast resistor, 1971.
133,668 FASTBACK receives "S" type technical mods. Points, coils, etc. 135,140 First ROADSTER with low
pipes, upswept silencers, reverse cone absorption type.
139,571 FASTBACK Mk II fitted with Roadster exhaust system.
142,534 Mk II ROADSTER, Mk 111 FASTBACK, same 4:10 tyres on both wheels. Fork gaiters and F/bed type
yokes dropped, bare chrome stanchions introduced. Lucas h/bar lever switches introduced and indicators.
Centre stand mounted on g/box Shock absorber fitted in rear wheel.
Jan, '72 Consecutive engine numbers which had continued since W.W. II abandoned. New system and
numbers introduced.
200,001 FASTBACK Mk. IV, ROADSTER Mk. IV. New crankcase castings, with breather behind c/case (not from
end of camshaft). First double roller main bearings.
200,976 First COMBAT engine. Compression ration raised to 10:1 by machining head, double S camshaft fitted.
Black barrel-. 32mm carbs. Disc brake right hand side behind fork leg, Models now 'Fastback' and
'Roadster.'
212,278 INTERSTATE. Larger black or blue (5 gal) tank, seat longer. Low level Interstate silencers. (Most Combat
engines were later modified to standard engine specification and stronger main bearings fitted, i.e.
Superblends (barreled rollers). Small sump plug introduced, later models with car type oil filter. 16H type
(pre-war) front brake shoes with speedo drive clearance no longer used in Commando rear wheel.
(Shame!).
220,000 COMBAT engine abandoned but 32mm carbs retained. Roadster Mk. V, Interstate Mk. V only. No more
Fastbacks. Black instrument pods.
230,000 Square rear light. Different fork geometry. Box section head steady. 230,935 Last 750 COMMANDO
(unless you know better.)
300,001 April '73, first 850 Mk. I. Barrel fixings altered, bronze clutch plates fitted, balance pipe in exhaust pipes.
Strengthened swinging arm. larger sump plug reintroduced.
306,591 Mk. IA. Larger, quiet air box and annular discharge (bean can) silencers. Candy apple red tank also
available. Chain guard plastic extension added. 2nd gear ratio raised by one tooth (to reduce noise
readings).
307,091 Slimmer Interstate tank, 4 1/2 gals approx.
307,311 850 Mk. IIA. Improved paint, 30mm ports but 32mm carbs (for flexibility). Various small detail mods.,
such as mud flaps, third sleeve gear bush added. Black and blue tanks dropped, red and a few "traditional"
silver tanks. Fork gaiters reintroduced and lower bars. Tach drive oil leak reduced (supposedly).
309,600 Larger, stronger kick start.
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