Kick Starting

Hi Roger - The factory delivered compression ratio of a 650SS was 8.9:1 whereas the Atlas was 7.5:1. I doubt very much that you would notice any such difference using the kickstart.  Many Atlas bikes had Commando pistons fitted by the owners, at rebore intervals, because the original Norton or Hepolite items became very rare.  The factory delivered compression ratio on a 750cc Commando was 8.9:1,  by the way and so as time went by most Atlas bikes were the same as the 650SS. You could try using an extended kickstart lever from a Commando on your SS as that may help.  Good luck, Howard    

Strangely i find that although the Atlas with its Commando pistons is hard to get moving from cold .once its on the move the heavy flywheel keeps it ticking over even if one cylinder is a bit reluctant. . Cant make much of a comparison with the SS as up to now I have not managed to fire it up as its very stiff . A shift to 20/50 oil may help.