i have a 1200s 2000 model twin spark (2per head)etc its light years beta than a standard 1200

 

I bought the Service Manual for my bike, and the more I read, and more I tinker with it, the more cool stuff I discover this model has.

 

The 1200S has a whole different ignition system than a standard 1200. It has twin plugs because it has higher compression than does a standard 1200. The heads in the 1200S had much smaller chambers to achieve this higher compression using the same 1200 pistons. It was found that some of the air/fuel mixture could be "shadowed" from the spark of a one plug design so Harley added the second plug to overcome this issue.

Later Harely, via Buell, went to the Thunderstorm piston/head combo because keeping the chambers larger while reducing compression with a domed piston was the better way to achieve the same results and eleminate the need for two plugs.

The 1200S was also the first Sportster to come stock with the W-grind cams. These cams later were introduced into the standard 1200 line (2004) and then the entire Sportster lineup (2007).