Norton Commando Technical

Engine
Primary Transmission And Rear Chain
Gearbox
Carburetor And Air Filter
Frame/ Isolastics
Forks/ Shocks
Brakes Wheels And Tires
Electrical
Torque Settings
Capacities


Norton Commando Engine Specs
	750	850
Capacity	745cc (45 cu. in.)	828cc (50.5 cu. in.)
Bore	2.875 in. (73mm)	3.030 in. (77mm)
Stroke	3.503 in. (89mm)	3.503 in. (89mm)
Max. Torque(5000 rpm)	48 lb./ft. (Combat 49lb)	56 lb./ft.
Compression Ratio	9:1 (Combat 10:1)	8.5:1
Maximum Speed	112 MPH (Standard)	122 MPH
Spark Plug	Champion N7Y or Equivalent.
Spark Plug Gap	.023 – .028 in.
Contact Breaker Gap	.014 – .016 in.
Ignition Timing	28 degrees BTDC (Fully Advanced)
Valve Clearances (Cold)	750	850
Inlet	.006 in. (Combat .008)	.006 in.
Exhaust	.008 in. (Combat .010)	.008 in.
Camshaft Chain Adj.	3/16 in. (4.8mm) play at top of chain.
Valve Seat Angles	45 degrees inlet and exhaust



Norton Commando Primary
Engine Sprocket	26 Teeth
Clutch Housing	57 Teeth
Primary Chain	Triple Row, 92 Pitches, .375in. x .250in.
Rear Chain	99 Pitches, .400in. x .380 in.
Clutch Pushrod Length	9.813/ 9.803 in. (244.250/ 243.996 mm)
Clutch Pushrod Diameter	.237/ .232 in. (6.019/ 5.892 mm)
Clutch Ball Bearing	1/2 in. (12.70) Diameter
Clutch Plates	4 fiber clutch, 5 metal clutch (Sintered Bronze)
Clutch Adjuster	1/2 in. x 20 UNF 2A
Clutch Adjuster Length	.904 in. x .894 in ( 22.962/ 22.708 mm)



Norton Commando Gearbox
Estimated Speeds Using 19-23 Tooth Gearbox Sprockets
Sprocket Size	Overall Gear Ratio	6000 rpm	6500 rpm	7000 rpm
19	4.84	92 mph	99 mph	107 mph
20	4.60	97 mph	105 mph	113 mph
21	4.38	102 mph	110 mph	119 mph
22	4.18	106 mph	115 mph	121 mph
23	3.99	112 mph	121 mph	130 mph
( I recommend using a 20 or 21 tooth sprocket depending on where you live)

Number Of Teeth On Pinions
First Layshaft 28 teeth
Second Layshaft 24 teeth
Third Layshaft 20 teeth
Fourth Layshaft 14 teeth
First Mainshaft 14 teeth
Second Mainshaft 18 teeth
Third Mainshaft 21 teeth
Fourth Mainshaft 23 teeth
Ball Journal Bearings
Mainshaft (Clutch End) 11/4 x 21/2 x 5/8 in.
Mainshaft (Kickstarter) 5/8 x9/16 x 7/16 in.
Layshaft (Clutch) 17mm x 40mm x 12mm



Norton Commando Frame & Isolastics
Front Isolastic
Shim Thickness Available	.005, .010, .020, .030, in.
Free Play	.010 in.
Bolt	7.13 in., 1/2 in. x 20 UNF.
Buffer Quantity	2
Buffer Diameter	1 11/16 in.
Buffer Thickness	1/2 in.
Bush Quantity	2
Bush Thickness	5/8 in. tapered to .510 in.
Spacer	2.573/ 2.553
Rear Isolastic
Bolt Torque Setting	300 in./ lb.
Shim Thickness Available	.005, .010, .020, .030, in.
Free Play	.010 in.
Stud	13 in.
Stud Thread Size	1/2 in. x 20 UNF 2A
Buffer Quantity	2
Buffer Diameter	1 5/16 in.
Buffer Thickness	1/2 in.
Bush Quantity	3
Bush Thickness	1/2 in. tapered to .410 in.
Spacer	1.560 in./ 1.550 in.
Dimensions
Height	40.75 in.
Length	87.5 in.
Wheelbase	56.75 in.
Weight (Roadster)	420 lb
Weight (Interstate)	435 lb.
Width	26 in.
Turning Circle	17ft.10 in.
Center of Gravity	19 3/4 in.
Seat Height	33 1/2 in.



Norton Commando Forks and Shocks
Forks ( Telescopic with internal Springs Hydraulically damped)
Total Fork Travel	6 in.
Fork Leg Oil Capacity	150 cc in each leg
Springs	75 1/2 Coils
	18.687 in. free length
	36.5 lb./ in
Shocks (Girling Oil filled with External Springs)
Spring Free Length	8.75 in.
Rate	126 lb. per in. (depends on adjustment)
Fitted Length	8.4 in.
Total Length	13 in.



Norton Commando Brakes Wheels Tires
Front Wheel
Rim Size	WM2 – 19 in.
L.H. Wheel Bearing	17x40x12 mm.
R.H. Wheel Bearing	NM 17721
Spindle	.66671/ 6670 in.
Tire Size	4.10 x 19 in.
Tire Pressure	26 PSI
Tire Diameter	26.46 in. (Dunlop)
Tire Width	4 in.
Front Brake (Disc)
Pad friction area	1.65 in.
Pad Thickness (New with Backing)	.38/ .37 in.
Pad Minimum Thickness	.0625 in.
Disc Diameter	10.70 in.
Disc Width	.260/ .250 in.
Brake Fluid	Lockheed 329 Quality
Front Brake (Drum)
Type	Twin Leading Shoe
Drum Diameter	8 in.
Brake lining area Total	18.69 Sq. in.
Rear Wheel
Rim Size	WM2 – 19in.
Wheel Bearings	17x40x12 mm
Sprocket Bearing	NM 177721
Tire Size	4.10x19in.
Tire Pressure	26 lbs./PSI
Tire Diameter	26.46 in.
Tire Width	4 in.
Rear Brake
Drum Internal Diameter (New)	7.007/ 6.997 in.
Brake lining area Total	13.6 Sq.in.



Norton Commando Electrical Lucas
General
Voltage	12 V Positive earth/ ground
Alternator	RM 21
Rectifier	2 DS 506
Zener Diode	Z D 715
Battery Rating	10 Amp Hour at !0 hour rate
Coil	17 M6
Ballast Resistor	3 BR
Contact Breaker	6 CA or 10CA
Warning Light Assimilator	3 AW
Fuse	35 Amp.
Flasher Unit	8FL
Bulbs
Headlight	12 V 45/40 Watt
Tail/ Stop light	12V 21/ 6 Watt Offset
Parking	12V 6 Watt Bayonet
Direction Indicators	12V 21 Watt
Warning Lights	12V 2 Watt



Norton Commando Torque Settings
3/8 in. Cylinder head nuts & bolts	30 ft./lb.
5/16 in. Cylinder head bolts	20 ft./lb.
3/8 in. Cylinder base nuts	25 ft./lb.
5/16 in. Cylinder base nuts	20 ft. /lb.
Cylinder through bolt (850cc)	30 ft./lb.
Con rod nuts	25 ft./lb.
Rocker cover plate bolt	8 ft./lb.
Crankshaft nuts	25 ft./lb.
Cam Chain tensioner nuts	15 ft./lb.
Oil Pump stud nuts	15 ft./lb.
Rocker feed banjo bolts	15 ft./lb.
Engine mount bolts	25 ft./lb.
Rotor nut	80 ft./lb.
Alternator stud nuts	15 ft./lb.
Clutch to Mainshaft nut	70 ft./lb.
Mainshaft nut	40/50 ft./lb.
Counter shaft sprocket nut	80 ft./lb.
Gearbox inner cover nuts	12 ft./lb.
Top gearbox fixing bolts	55 ft./lb.
Rear shock nuts	30 ft./lb.
Isolastic bolts	25 ft./lb.
Fork Top nuts	30 ft./lb.
Fork Yoke Pinch bolts	30 ft. /lb.
Steering head main nut	30 ft./lb.
Disk Caliper mounting bolts	30 ft./lb.
Disk Caliper end plug	26 ft./lb.
Disc Mounting nuts	20 ft./lb.
Drum brake cam nuts	30 ft./lb.
Sidestand nut	50 ft./lb.
Zenor Diode nut	2 ft./lb.
Coil bracket nuts	1 ft./lb.
Oil pressure release valve	25 ft./lb.

Norton Commando Engine Specs