Mag A and mag B

Hi Randy

A look in your heavy manual shows it depends on the engine.  On a ULS A fires top 1 and 2, bottom 3 and 4.  B fires the bottom 1 and 2 and top 3 and 4.  On type 914 A fires all top, B all bottom.  

Cheers

Only on the 914. On the 912 carburetted engines the modules are split between the top and bottom plugs, so that module A fires the top plugs for cylinders 1 and 2 and the bottom plugs for cylinders 3 and 4, with module B doing the opposite.

On the 914, the top and bottom plugs have different ignition timing, so module A (the top module) fires the top plugs and module B (the bottom module) fires the bottom plugs.