Trailtech tachometer install....info needed.

Installing a Trailtech tach(model TTO). The instructions have you pick between .5,#1 and #2 PPR( pulses per revolution)....does the TW have a "wasted spark" system?.I choose #1 to start with....the upper rpm's seem to be accurate?...it's when the bike is idling that's in question?.I do not have a trained ear for such things....the manual says the TW idles between 1350 and 1550 rpm's. This tach is showing a 1600ish idle?.....the bike doesn't "sound" like it is idling that high....then again,it may be my hearing.The tach has a lead that you wrap around the plug wire "X" amount of times(added info).Any suggestions.