97 883/1200 conver. w/ 10.5:1 Weisco pistons & S&S Super E Carb ~ stock ignition it had been sitting a while due to my surgery I had a few months back ~ the last service I had was before I got hurt ~ anyway , I changed the oil pulled the plugs and checked the gap on the old ones and one (the rear head) was at .025 and the front head was at .036 ~~ was this done on purpose due to the hi-compression pistons ??? Or was the shop that did the work just morons? And if so what is the best setting on the gap for this situation?? I usually set it at .040 on both but that was before the big bore kit and pistons ~~ Thanks in advance guys! Tony in Knoxville

 

well 0.040 is the standard gap and that's what i've stuck with after my conversion. A smaller gap will give you a hotter spark, but will also increase the heat of the tip, in some cases leading to preignition if it gets too hot and can't disapate the heat quick enough.