Related Manuals for Norton Commando 1973
Summarization of Contents
Group 1 - Crank assembly including pistons, camshaft and timing gear
CON RODS
Details on con rods, their condition, and potential improvements for fatigue life.
BIG ENDS
Information on big end wear, maintenance, and the importance of changing shells.
CRANKSHAFTS
Guidance on crankshaft regrinding, common causes of breakage, and bolt care.
IDLER GEAR SPINDLE
Instructions for fitting and securing the idler gear spindle and addressing slackness.
CAMSHAFTS
Discussion on camshaft types, hardness, the 'SS' cam, and fitting advice.
CAM BUSHES
Details on cam bushes, their types, fitting, and potential issues with oil supply.
PISTONS
Advice on selecting pistons, differences between types, and oil control ring considerations.
CON ROD NUTS
Notes on the reuse of con rod nuts and recommended practices.
The Most Significant Changes in Commando Models
Engine Nos.
Chronological listing of engine numbers and associated model changes and features.
Group 2 - Barrels, gaskets and head parts
CYLINDER BASE GASKET
Information on base gaskets, their deletion, reintroduction, and compatibility.
CYLINDER HEAD GASKET
Types of head gaskets, their effect on compression, and suitability.
Cylinder heads
Details on different cylinder head types, port sizes, and chamber depths.
VALVE GUIDES
Advice on valve guides, their thickness, seals, and material choices.
VALVES
Information on stellited valves, part numbers, and handling advice.
PUSHRODS
Common issues with pushrods, adjustments, and compatibility with head modifications.
ROCKERS
Tips on rockers, valve contact, adjusters, and checking for wear.
HEAD BOLTS AND NUTS
Notes on head bolt and nut types, threads, and potential confusion.
EXHAUST THREADS
Advice on preventing exhaust thread stripping and securing exhaust rings.
Head gaskets
Advice on annealing copper gaskets and preventing leaks.
Group 3 - Timing cover, all therein and rocker feed
TIMING COVER
Details on timing cover, oil seals, gaskets, and potential oil leaks.
POINTS COVER
Information on points cover types, adjustment, and auto advance units.
OIL PUMP
Discussion on oil pump reconditioning, shims, and pressure gauges.
ROCKER FEED PIPES
Guidance on fitting rocker feed pipes, materials, and common failure points.
Clutch drag
Cause of clutch drag and a suggested remedy involving oil type.
Group 4 - Crankcases, breathing and main bearings
CRANKCASES
Assessment of crankcase design, stress points, and common cracking issues.
MAIN BEARINGS
Recommendations for main bearings, types, and fitting advice.
BREATHING
Discussion on crankcase breathing systems and oil return issues.
Rev Counter Drive Oil Leaks
Troubleshooting oil leaks from the rev counter drive and potential fixes.
Groups 5, 6, 7 - Gearbox
THE GEARBOX
Historical overview of the gearbox design and its limitations.
SHELL, CLUSTER, SPROCKETS
Notes on gearbox shell, bushes, studs, and thread types.
SLEEVE GEAR & LAYSHAFT BEARINGS
Issues with sleeve gear bushes, layshaft bearings, and potential cures.
KICKSTARTER PAWL
Discussion on kickstarter pawl material, breakage, and jamming issues.
GEARBOX 2ND GEAR
Notes on gearbox 2nd gear changes and interchangeability.
Group 8 - Primary case and clutch
PRIMARY CASE
Common oil leaks from the primary chain case and their causes.
CLUTCH
Discussion on clutch components, diaphragm springs, and modifications.
CLUTCH PLATES
Notes on clutch plates, material types, and wear issues.
CLUTCH ITSELF
Modifications to the clutch, friction plates, and potential notching problems.
Group 9 - Carburetors
CARBURETTORS
Discussion on Amal carbs, wear, flooding, and synchronization.
CARBURETTORS
Tips for twin carb tuning, slide synchronization, and air screw adjustments.
GROUP 10 - Engine mountings
ENGINE MOUNTINGS
Overview of the Isolastic mounting system and its development.
HEAD STEADY
Issues with early head steadies and recommendation for the box section type.
ISOLASTIC SHIMMING
Guidance on reducing gaps in the Isolastic assembly to prevent frame damage.
GROUP 11 - Frame, swinging arm and suspension
FRAME
Evolution of the Commando frame design, from early models to later improvements.
HIGH SPEED WEAVES
Factors affecting high-speed stability and handling, including tyres and rider input.
SWINGING ARM
Problems with the swinging arm spindle location and potential repairs.
REAR SUSPENSION UNITS
Notes on rear suspension units, spring ratings, and damper covers.
GROUP 12 - Footrest plates
FOOTREST PLATES
Details on footrest plate design, materials, and thread types.
THE FOOTRESTS
Common issues with footrests breaking and methods for repair or replacement.
GROUP 13 - The oil tank
THE OIL TANK
Reasons for mounting rubber failures and oil tank design.
THE OIL FILTER
Location and interchangeability of the oil filter element.
GROUPS 14, 15 and 16 - Forks and front wheel, including front brake
FORKS AND FRONT WHEEL
Assessment of Norton forks, steering bearings, and wheel spindle security.
FRONT WHEEL BEARING LOCKRING
Part number for lockring when reversing front brake.
FRONT DRUM BRAKES
Advice on front drum brake linings, modifications, and brake stiffening kits.
GROUP 17 - Rear hub, brake and sprocket
Rear hub, brake and sprocket
Notes on rear hub bearings, brake maintenance, and sprocket wear.
GROUP 18 - Handlebar controls
THE BRAKE AND CLUTCH LEVERS
Variations in brake and clutch levers, pivot position, and interchangeability.
CLUTCH CABLE
Issues with clutch cables, nylon lining, and recommendations for nipples.
GROUP 20 - Exhaust systems
EXHAUST SYSTEMS
Notes on exhaust systems, port threads, silencer types, and power reduction.
GROUPS 25, 26, and 27 - Electrics
ELECTRICS
Advice on HT leads, battery strap, RITA ignition, and wiring harness.
GROUP 29 - The tool kit
THE TOOL KIT
Modifications for Allen keys, tappet spanners, and other common tools.
Commando Service Notes - Mk III Addendum
COMMANDO MODIFICATION LIST Engine
List of engine modifications with part numbers and descriptions.
ENGINE
MAIN BEARINGS
Notes on main bearing issues, Loctite application, and bearing types.
TIMING CHAIN TENSIONER
Advice on timing chain tensioner use and potential damage from overtightening.
CAMSHAFTS
Issues with camshaft hardness and the need to check followers.
REV. COUNTER DRIVE
Potential fixes for leaking rev counter drive units.
PUSHRODS
Considerations for pushrods after head machining and potential wear issues.
PRIMARY CHAIN CASE
Causes of primary chain case rattles and solutions for hydraulic tensioners.
CLUTCH SLIP
Methods to correct clutch slip, including plate machining and oil types.
CLUTCH DRAG
Causes of clutch drag related to pushrod tube oil travel and solutions.
ALTERNATORS
Details on alternator rotor/stator gap, high output stators, and Zener diodes.
ELECTRIC START
Information on electric start conversion kits and part numbers.
ENGINE (Continued)
GEARBOX
Discussion on gearbox bearing failures, ratios, and gear changes.
KICKSTARTER PAWL
Advice on kickstarter pawl hardness and potential jamming.
ENGINE (Continued)
THE PAWL SPRING
Troubleshooting pawl spring issues and ensuring correct gear engagement.
GO-FASTER MODS, SILENCERS AND AIRBOXES
GO-FASTER MODS, SILENCERS AND AIRBOXES
Performance modifications including silencers and airboxes.
WHEELS AND BRAKES
WHEELS
Notes on front disc rust, wheel bearings, and rear axle material.
REAR DISC CALIPER
Maintenance for rear disc calipers, pads, and master cylinder issues.
TWIN LEADING SHOE FRONT BRAKE
Improving front brake effectiveness with a longer operating arm.
FRAME PARTS AND HANDLING
HANDLING
Improving handling with head steadies and frame geometry.
ISOLASTICS
Fitting Mk III Isolastics and checking adjuster rods for rust.
SWINGING ARM LUBRICATION
Methods to improve lubrication for swinging arm units.
SERVICE RELEASE No. N3/13
Camshaft interchangeability on 1971-1974 Commandos.
SOME TUNING TIPS FROM C. BRADDICK
"DOUBLES" CAMSHAFT
Issues with the "Doubles" camshaft, valve clearance, and springs.
HIGH-SPEED WEAVING
Factors affecting high-speed weaving, including tyre condition and handling.
REAR SUSPENSION UNITS
Using 100lb springs and Girling shocks for improved handling.
OIL-TANK
Oil escaping from the oil tank breather tube during cornering.
CLUTCH
Checking for buckled plates and advice on pressure plates.
ROCKERS
Adjusting rocker end for valve contact and using spacers.
CRANKCASES
Ensuring crankcases are free of tight spots when bolted together.
CARBURETTORS
CARBURETTORS
Tuning twin carbs for synchronized slide lift and even tickover.
CARBURATION
AMAL CONCENTRIC SETTINGS FOR NORTON COMMANDOS, EX-WORKS
Table of Amal concentric carb settings for various Commando models.
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