The 1968-1977 Norton Commando motorcycle repair manual by Haynes, covers the following models: 750cc Models:

• Norton Commando 750, Feb. 1968 to March 1969
• Norton Commando Fastback 750, March 1969 to March 1973
• Norton Commando Roadster 750, March 1970 to Oct. 1973
• Norton Commando Interstate 750, Jan. 1972 to Oct. 1973

850 Models:

• Norton Commando 850 Roadster, April 1973 to Oct. 1977
• Norton Commando 850 Hi-Rider, April 1973 to Feb. 1975
• Norton Commando 850 Interstate, April 1973 to Oct. 1977

Book Excerpt: 1968-1977 Norton Commando 750, 850 Repair Manual ENGINE

DISMANTLING THE ENGINE: REMOVING THE ALTERNATOR, CLUTCH AND PRIMARY CHAIN CASE

1. Remove the three nuts and washers which secure the left hand footrest and rear brake pedal to the light alloy mounting plate. In order to clear the primary chain case cover, the footrest assembly can be left hanging from the brake cable; the alternative is to remove the electrical snap connector from the stop lamp switch on the brake pedal and the brake cable from the rear brake operating arm so that the complete assembly can be detached and lifted away.
2. Place a large tray immediately below the underside of the crankcase joint. The crankcase has no drain plug and in consequence the full oil content will be released immediately when the two halves are separated.
3. Remove the center sleeve nut which retains the two chain case halves together and rock the chain case slightly to clear the two locating dowels, one at the top and one at the bottom. Immediately seal the brakes, the oil content will be released into the tray. Remove the outer cover completely, taking care that the rubber seal around the joining face or rear half of the chain case is not displaced and damaged.

CARBURETION AND LUBRICATION

DISMANTLING, RENOVATING AND REASSEMBLING THE OIL PUMP

1. Unless the oil pump gives trouble, it should not be dismantled unnecessarily. Oil pump faults can be divided into two categories; complete failure of the pump and a tendency for oil to leak through the pump whilst the machine is stationary, causing the crank case the crank case to fill with oil. The first type of fault is usually associated with some form of breakage in the oil pump drive, or the presence of metallic particles in the pump itself which has caused the gears to lock, shearing one of the drive spindles. The less serious oil leakage is caused by general wear and tear which can be rectified to an extent by taking up end float, as described in the following paragraph. Any fault attributed to the oil pump necessitates a complete strip down for examination.
2. Remove the oil pump as a complete unit from within the timing chest, as described in Chapter 1.11, paragraphs 1 and 2. The degree of end float can be ascertained by moving the oil pump driving gear in relation to the pump body; when the pump is new there should be a complete absence of end float.
3. To strip the pump, remove the four long screws which hold the oil pump together. The top cover can be lifted off together with the drive gear and spindle; the other pump gears can be lifted out, also the second spindle. The gears are keyed onto the spindles but are only a light push fit.
4. Wash all components in neat petrol and allow them to dry. It will be noted that the scavenge section of the pump is twice the capacity of the feed section, necessary to keep the crankcase clear of excess oil. In consequence, the scavenge pump gears have wider teeth.

BOOK REVIEW

The Norton Commando repair manual by Haynes is a great guide for the guy who's not a mechanic, but who would like to work on his motorcycle. I purchased the manual a while back to work on my 1975 Norton Commando 850, and it allowed me to go through the entire bike, even though I have no formal training. I first read the chapters covering the sections I wanted to work on in order to get familiarized with the components and how they fit together. The exploded views explained things nicely and the close-up pics helped see how those parts fit together while assembled. The text is another important part that explains which steps must be followed to disassemble the component and then put the whole thing back together and what torque settings are required. Since the book was originally written back when these bikes were new, I chose to ignore the specified oil for the primary case since it was recommended by several people who have and ride these bikes that the best choice was to use ATF instead. Additionally, I also used Yamabond to insure the primary case would be leak-free, something to really consider if you decide to use ATF instead of the heavier motor oil. I tried really hard to give the bike a proper tune-up, but a combination of worn Amal carbs and questionable electrics made that task almost impossibleandmdash;if I wanted the bike to idle under 2500 rpm. So I made the decision to replace the dual carbs with a single Mikuni kit and went ahead and upgraded to a Boyer electronic ignition. That solved the high-idle issue nicely. I recommend the Haynes Norton Commando 1968-1977 repair manual to anyone working on one of these motorcycles. I also used the Norton repair manual by Clymer, now available bundled with the Triumph and BSA manuals.

Subject: 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977 Norton Commando 750 and 850 service, maintenance, repair. ISBN-10: 0856961256 | ISBN-13: 9780856961250 | Haynes 125