1. Run it up to working temperature, drain and refill with fresh oil.
2. For long term storage, remove spark plugs and inject about 50cc of clean engine oil into each combustion chamber and rotate engine a few times.
3. Seal exhaust stubs with gaffer tape, ditto for carburettor intake.
4. Refit spark plugs finger tight after positioning engine at TDC.
5. About every 6 months, remove plugs and turn the engine over by hand a few times, park engine at TDC & refit plugs.
To recommission.
5. Install engine, remove plugs and place bundled-up rags by spark plug holes.
6. Spin engine over with starter to eject oil from combustion chambers.
7. Once carburettor is primed with fuel, refit plugs and try starting engine.
8. If plugs are fouled by remnants of oil in cylinder, fit clean plugs and try again, etc.
Edit:
5A would be "disconnect LT leads from coil".
Smiffy wrote:
What's the best way to "lay up" an A-series engine, to prevent seizure, valves stuck open etc. etc?