Yes it might make a differance on Idle....big deal!!! The main thing a single fire ignition does is, it lets the coil saturate better for higher rpm running without so many miss fires. It will let the bike pull a little better but its for higher rpms than anything else. Is it worth the money for a street bike or a mild build....NO! The only reason Harley has the single fire ignition on their big twins is because of the fuel injection models require it for setting each cylinder seperately......since they had to do that, to save money and not have to make two ignition systems they carried it over to the carbed big twins. We use it on the drag bikes because we are reving to 7200 rpms. any thing over 5200 rpms the single fire is a plus.....below that your waisting your money.Demon1200 said:Has anyone changed to the single fire ? What did it cost ? is it worth it?and so on.