I recently bought a Norton Commando 750 Roadster from 1971. The bike is in okay condition, but has not been started since 2011! So my question is, what should I do before I step on the kick starter for the first time?
1. Change oil 2. Replace the oil filter 3. Empty the old fuel from the fuel system and fill with new fuel 4. Replace spark plugs 5. Replace the battery (fully charged)
What about old solidified oil in the system, do I need to get red of that before starting up?
1. Drain the sump of oil(don't kick it until you do) 2. (fuel) if it has a fiberglass tank, don't put ANY fuel that has alcohol (methanol) in it. 3. ("What about old solidified oil in the system") not sure what you mean, but if this is crud in the bottom of the oil tank, remove the tank and wash it out with hot soapy water.
Remove both exhaust rocker inspection covers and pour a small amount of engine oil into the head on each side which will help to lubricate the tappets/lifters and cam lobes on the initial start-up.
Much of what has been advised here is in Waking The Sleeping Beast. The original article was written by a long-time Brit. bike owner, builder, racer and dealer and - although primarily aimed at Triumph/BSA triple owners - much of his advice applies to any engine, as you can see.
One thing you might want to consider is being generous with the "amount of engine oil into the head". The oil will drain to the sump; as soon as the engine starts, the crank can immediately start flinging around any it touches to splash-lubricate bearings that require it and the oil pump can immediately start scavenging the oil back to the tank ... which reduces the heart-stopping period between starting the engine and returned oil appearing back in the tank!