1920s Valve and Ignition Timing Charts.

Compared to modern day motorcycle manuals which are very complete with detailed photographs, descriptions and all the Health and Safety precautions that one trembles at, older vintage manuals are of the most basic type, but then so are the motorcycles. When it comes to working on them in modern times we sometimes struggle especially when it comes to accurate valve and ignition timing. Ignition timing can be worked out and adjusted as you go but what about valve timing? It is something that we really need to know to get the best out of these old engines. Well, in 1931 Newnes published a 14 part series covering motorcycle repair of what was probably the 14 most popular makes (or perhaps the 14 most helpful manufacturers) and with each series was a valve and ignition timing chart for a different make.

Models covered are –  AJS 1919~1930, Blackburne, Ariel, BSA 1915~1930, JAP 1926~1931, Matchless, P&M, Douglas, New Imperial, Norton, Raleigh, Rudge, Royal Enfield and Sunbeam.

With early oiling systems including total loss and ‘oil mist’ camshaft wear was inevitable after 80 years so hopefully this information will be the magic tonic you will need to get that old banger running better. And if you are the poor soul that bought a bike in parts with one set of crankcases and 5 different camshafts, well this could be your lucky day.


Click on the cover below to see the 14 different manufacturers charts.

It is a 3.44M PDF so you will need Adobe Acrobat Reader to view it.