All British bikes have a lot of common factors. Air cooled , push rod motors run by lucas points and amal carbs..The primary technology on almost all of them carried on from the 30's. The main cause of failure is improper maintenance. We have technology and information now to keep them maintained easier.
Electronic ignition is the first and foremost easiest way to limit the amount of constant maintenance. Some people want to avoid the inevitable but the electronic ignition is no wear and tear and there is not re timing on every tune up. When the points wear the timing changes, when the timing changes you stress the motor. Points also corrode, so when your bike sits over the winter you have may no spark. You also have to make sure your condensors are good so the points can do their job. All this is eliminated with electronic ignition.
Valve adjustment is the second most over looked thing that absolutely needs to be checked. Having a little play in your valve adjustment is absolutely necessary . The valves rely on being fully closed for a certain small period for cooling purposes. If the valve does not cool the engine will over heat. Also when the adjustment gets to tight you lose compression and you start to flatten your cam lobes. So get familiar with the process of valve adjustments.
Routine oil changes, the standard was 1500 miles. With modern oils that are designed and meant to carry sludge, changing your oil before high sludge content is formed and captured in your crank's sludge trap is a great idea. Don't be afraid to spend the money on oil changes every 1000. We recommend a genuine motorcycle oil like Castrol 4T for vintage british bikes.
Carb maintenance is more critical and usually ignored more than you think. One of the most mistaken symptoms of carb troubles are carbs that are running rich. The biggest culprit is normally over looked, that's the needle jet. The needle jet is subject to wear, the main jet is not. The pulse of the intake forces the slide needle to beat the needle jet into a bigger diameter and over time it allows more volume of gas to pass through. Also, as the carb is used the slide itself is wearing out and should be replaced before it starts to damage the body. The factory suggested at least checking both items at 3000 miles. We are also faced with the worst carb enemy , ethanol. The best way combat ethanol is to keep your bike running regularly. A constant fresh tank of gas is going to give you less troubles. Ethanol is water based and your brass jets don't appreciate that. Ethanol also attracts moisture from the air and the longer it sits the higher the water content.
Don't be afraid to get a factory work shop manual, it's accurate. Having a clymer or haynes a supplement is ok but nothing is as good as factory. Follow the routine maintenance, treat your bike the way you would your reliable automobile if something breaks, fix it. New alternators in newer vehicles work or they don't. Old british alternators can give a sub par charge that makes people say ... "well it's working but its just not keeping the battery charged". Change it. If your carbs are done , get new ones. A well maintained bike will keep you happy and keep you riding. Don Hutchinson told me (and its a 100% truth with vintage british bikes) a well maintained bike won't blue pipes. It's truly something to have british motorcycle that you can rely on and when done right , they can be very reliable......