There are advantages to running an old bike that was in production for over 25 years, especially ones as popular as the BMW Airheads.   For example, parts supply is good, and many parts were updated or improved over the years.   Often these can be retro fitted to older models either directly, or with a little ingenuity.   As an early example of the breed, my 1974 R75 thus has scope for improvement in a number of areas. Take starting.   On cold mornings, pressing the starter button would produce only a lazy response from the engine.   The reason for this lies in the technology of the time as well as in the bikes design.   The original starter motor in my bike (made by Bosch), used electro magnets.   This meant that to get the bike to go the starter motors coils had to charge up whilst still leaving enough current in the system to produce a decent spark at the plugs.   The compromise here is that to leave enough juice in the battery for t...