1930 Gardner 3L2 test run after overhaul 

They are for decompression but on a Gardner L2 like this when moved from down to 90 degrees it is decompressed, but when pull up and over like you see in the video it moves the intake valve rocker arms over which you can see in the video. This alters the inlet valve timing for cold start and improves fuel burn whilst the engine is cold.

@@MPSVintageDiesels Thanks for the excellent explanation, very interesting.

28.5hp @ 1000rpm, 3 Cylinder

@@MPSVintageDiesels thanks🙏🙏🙏