Vintage British Street Bikes Repair Manual: BSA, Norton & Triumph

• BSA 500cc, 650cc unit twins, 1963-1972
• Norton 750cc, 850cc Commando, 1969-1975
• Triumph 500cc, 650cc, 750cc twins, 1963-1979

Regular maintenance is the best guarantee of a trouble-free motorcycle. An afternoon spent cleaning and adjusting can minimize costly mechanical problems and unexpected breakdowns on the road.

This chapter describes all required preventative mantainence and procedures for engine tune-up. Anyone with average mechanical ability can perform the procedures.


MAINTENANCE AND LUBRICATION INTERVALS

Maintenance and lubrication intervals are shown in Table1 for bikes used on the highway and in Table 2 for off road use. Because of dust and dirt, off-road usage requires more frequent service for trouble-free performance.

Figure 1 shows lubrication points and gives the correct grade or type lubricant required. Information in Table3 lists recommended lubricants. Selection need not be limited to these brands if comparable products are available.

In addition to the items listed in the pertinent table (Tables 1 or 2), the following parts should be carefully inspected after 24 months.

• Brake cables
• Brake light switches
• Carburetor rubber dust caps
• Fuel lines

The basic tools needed are listed in Chapter one. In addition, equipment required for a complete tune-up includes a static timing light, a strobe light, dwell tachometer, carburetor float gauge, and sets of flat and round feeler gauges.

Diagnosing motorcycle ills is relatively simple if you use orderly procedures and keep a few basic principals in mind. Never assume anything. Don't overlook the obvious.

If you are riding along and the bike quits, check the easiest, most accessible problem spots first. Is there gasoline in the tank? Is the gas petcock in the on or reserve position? Has a spark plug wire fallen off? Check the ignition switch. Sometimes the weight of keys on a key ring may turn the ignition off suddenly.

If nothing obvious turns up in a cursory check, look a little further. Learning to recognize and describe symptoms will make repairs easier for you or a mechanic at the shop.

Describe problems accurately and fully. Saying that "it wont run" isn't the same as saying "it quit on the highway at high speed and wouldn't start," or that "it sat in my garage for three months and then wouldn't start." Gather as many symptoms together as possible to aid in diagnosis.

Note whether the engine lost power gradually or all at once, what color smoke (if any) came from the exhausts, and so on. Remember that the more complicated the machine is, the easier it is to troubleshoot because symptoms point to specific problems.

• General Information
• Lubrication and Maintenance
• Engine
• Clutch and Transmission
• Fuel and Exhaust Systems
• Ignition System
• Cooling System
• Front Suspension and Steering
• Rear Suspension
• Brakes
• Body and Frame
• Wiring Diagrams