Pulses Per Revolution, Tach Help

[Biglefty25]

I've got 2 saws, a MS 291 and MS 461, and recently bought a tachometer. I never have really messed with the carb settings and have just left them at what they were set at from place of purchase. I'm curious now what these saws are running for RPMs.

I have a dumb question. What setting do I need to set my tachometer at to read the RPMs properly for these 2 saws (tach has multiple settings): 1 pulse per revolution (360), 2 pulses per revolution (180), or 1 pulse per 2 revolutions (720)?

I've been searching online and have found no definite answer. Any help would be greatly appreciated. I'm a rookie at messing with carb settings and don't want to mess anything up.

Thanks!

 

[ANewSawyer]

One pulse per revolution for most small engines. Small four strokes often have a waste spark, so the same setting will usually work.