Norton Commando Models

Commando changes

Sources: scanned typewritten sheet with additional handwritten notations + INOA "Tech Digest" + Steven Hudson - "Commando Service Notes" + Roy Bacon - "Illustrated Norton Buyers Guide", 1991

Engine number



Year 1968

126125 9 March 1968 Consigned to Doran & Wright
126125 20M3 750 1st Commando. Engine prefix 20M3; external rev-counter drive; points in old magneto position; front wheel 3.00x 19in; rear wheel 3.50x 19in; short roadholders with longer stanchion; older style silencers. Only one model (later known as Fastback). 745cc [73mmx89mm] same dimensions as the Atlas
128646 750 new type sleve gear & layshaft pinion tooth form

Year 1969

129897 750 Rear wheel security bolt; new frame; added lower small tube to steering head. Approx Jan 1969
130979 750 Engine prefix 20M3S. Points in timing cover; integral rpm drive; Apex oil control rings. Models: Fastback, S Type and Roadster.
131180 First Fastback model designation. Approx March 1969.
131257 First S model: smaller rounded (Roadster type) tank; high level parallel pipes on left hand side with reverse cone shape silencers; first with ignition points on end of camshaft; tachometer drive inboard; six volt coilas with ballast resistor.
132576 750 fibre clutch friction plate
133668 750 Fastback model receives "S" type modifications: points, coils. Low exhaust pipes, upswept silencers, reverse cones,

Year 1970

135088 Last S model
135140 First Roadster
136618 Starter motor blanking plate fitted. Original starter was to fit into old magneto recess.
138973 Tapered middle compression ring fitted
139571 Fastback Mk II Reverse cone silencers from Roadster fitted. September 1970
140061 Plastic rocker feed pipe

Year 1971

141783 750 New style front forks without fork gaiters and featherbed type yokes with bare chrome stanchions; non adjustable sealed steering head bearings; 4.10 front tyre (same as rear); Lucas handlebar switches; indicators; centre stand mounted on engine plates (was on frame); shock absorber fitted in rear wheel.
142534 Roadster Mk II; Fastback Mk III New style front forks - non adjustable sealed steering head bearings, with 4.10 front tyre, Lucas handlebar switches, centre stand on engine plates (was on frame); new oil tank; right hand cover for Fastback.
145234 First SS model
146074 First Hi-Rider model. Models are Fastback, Roadster, SS and Hi-Rider, also Fastback LR (steel tank).
146584 S.E. spring expander oil control rings
147730 rear brake drums screwed and riveted
147846 toughened kick-start pawl
148895 modified intake valve guide
149670 oil seals on intake valves
150120 oil pump gasket fitted
150723 Last SS model
150765 Battery tray /airbox back plate modified
151175 Increased chamfer on tappets to increase oil drain from cylinder head
152000 rear drum strengthened webs
152499 replaceable foot pegs
153150 riveted clutch backplate
153324 tachometer housing gasket
153362 chain case cap O-rings introduced

Year 1972

200001 Fastback Mk IV; Roadster Mk IV New crankcase castings with breather moved to between gearbox plates behind engine (was on left hand end of camshaft); Engine number Prefix discontinued; "Optional" disc brake and combat engine; Fastback, Roadster
200001 750 Revised shape handlebars (Tomaselli)
200001 750 disc brake first offered (with first Interstate)
200004 750 Cylinder head with increased intake valve support (deleting 2NM23392 heat insulating washers.
Oil feed return pipes common sized to 17 inches.
Roller bearings introduced on timing side mains (not Superblend)
200708 750 Tappet locating plate replaces NMT2142
200976 750 First Combat model: compression raised to 10:1 by machining head; double S camshaft fitted; black barrel; 32mm carbs.
201778 750 Clutch plates scrolledoil slinger groove
202116 750 Four terminal master switch
202341 750 valve spring bottom seal washer thinned to accommodate cylinder head variations to 202666
202666 750 Cylinder head amended to accommodate NMT2071 heat insulating washers (reverted to 06088 1971 style)
202760 750 revised front brake lever - disc master cylinder
203136 750 front drum brake support plate introduced
204049 750 Grooved cam &: plain bushes changed to smooth can journals, grooved bushes
207197 750 Superblend (barrel roller) main bearings introduced
211110 750 First detuned post-Combat 750 engine
212278 750 Clutch plates scrolledoil slinger groove; bronze clutch friction plates; crankshaft to flywheel assembly changes to dowels & studs; flame ring head gaskets; RM21 (125 watts 5000RPM) alternator
212278 750 Interstate Interstate: larger 5 gallon tank; longer seat; low level Interstate silencers; turn signal indicators. Small sump plug introduced; later models had car type oil filter; rear brake shoes lost girder fork speedo gear clearance bend.

Year 1973

220000 Roadster Mk V; Interstate Mk V Combat engine abandoned; 32mm carbs from Combat retained for all and they worked well with reduced compression and raised gearing; Black Instrument pods; turn signal indicators optional on all; disc brake on all but Hi-Rider which retained 8 inch front brake.
Models are Roadster, Interstate and Hi-Rider. Fastbacks dropped from range.
221317 750 stellite tipped intake valves introduced
221545 750 improved centre stand P/N 064031
230000 square rear light; altered fork geometry; improved box section head steady
230935 Last 750 last 750 Commando
300000 Mk I 850 first 850 motor [828cc /829cc 73mmx77mm]; balanced pipe in exhaust system; barrel fixings altered; bronze clutch plates;strengthened swing arm; larger sump plug reintroduced. Roadster, Interstate, Hi-Rider all disc brake. April 1973
300003 Mk I 850 strengthened swing arm
301700 Mk I 850 Quick Action throttle introduced
302000 Mk I 850 improved rear chain oiler
305428 Mk I 850 improved rear wheel bearing spacer
306591 Mk IA 850 Homolgated model for Europe with larger, quieter black air-box and peripheral (annular) discharge silencers (bean can); chain guard plastic extension added; 2nd gear raised by one tooth (to reduce noise readings). Roadster and Interstate only.
307091 slimmer Interstate tank, 4-1/2 gallons approximately

Year 1974

307311 Mk II 850;
Mk IIA 850
longer battery crossbar; improved paint; 30mm ports but 32mm carbs (for flexibility);various small detail mods eg mudflaps; third sleeve gear bush added; black and blue tanks dropped; red and a few "traditional" silver tanks; fork gaiters reintroduced and lower handle bars; tachometer drive oil leak reduced (?). 850 motor with black barrel, available as homolgated model Roadster and Interstate only, called Mk IIA for Europe. For U.S.A. with old type silencers and air filter, Roadster, Interstate and Hi-Rider called Mk II.
309600 larger stronger kick start

Year 1975

Mk III electric start (left shift) and Mk II kick-start (right-shift) offered for sale January 1975
325001 Mk III 850 First electric start; left-hand shift; rear disc; front disc on left side; adjustable isolastics; silicon bronze valve guides; RM23 alternator
336539 Last commando