4 stroke, single cylinder (lifan?) 200cc

What do I set the new electronic tacho for, one spark per cycle, one per two cycles or two sparks per cycle? I always thought it was one per but after reading up, I am confused! Suck squeeze bang blow?

If no-one knows and I have to set it up the backwards way, by looking at the revs indicated at top cruising speed, what should it be showing? 8000 or so?