Suzuki 2 Strokes

This post is not asking about new aftermarket tachos but addresses electronic tachos that we tightwads bought or acquired cheaply and wish to use on our modified bikes.

So a triple fires once per cylinder per revolution. Nothing strange about that.

And most in line 4 fours strokes pre-2000 or so had two double ended coils that also fired once per revolution. the same applies to an RGV250 which has two pickups and two coils, each of which fires once per revolution.

So far so good. So any tacho for an inline four 4 stroke or V twin 2 stroke will probably work fine on a triple or even a twin two stroke. That's good news for people running points or a 12v Dyna system, but does not apply necessarily to CDI or magneto ignitions.

If the bike has a pickup per cylinder, one of the above tachos will work, but if the ignition fires twice (or more) per revolution, the tacho will over read by 2:1 or more.

There's an RZ350 on the net that used an R1 tacho and for the life of me I can't work out how he made that work. One is 2 pulses per rev and the other is one per. Anyone got any idea how that worked?

A Polaris 2 pulse tacho would work with a twin firing twice per revolution I thinlk, but 6 pulse tachos won't be close.

Richard i remember some generic tachs offered for vehicles years ago that had a switch for the cylinders in use and you apply the position for the engine cylinder count.
The little internal switch circuit board was nothing more than a few basic parts, so it could be built quite easily and adapted to the engine in question.

I think it is a 91 GSXR1100 tach i use on the yellow bike .

So how did the guy with the RZ350 manage to make an R1 tacho work??

I have a 2001 R1 tacho for the "Sport Custom" (previously known as Phirst Phat Trakka, and desperately in need of a decent name). According to my logic, it should work fine if I use one pick up per coil.

For the Phat Trakka, I really want the front end to be old skool tuff - no nancy boy instrument clusters. That's why I liked the 5 inch Polaris tacho. It's simple and solid and functional - but it needs 6 pulses per revolution.

Or I find a way to gut it and replace the guts with a 4 stroke 4 tachos.

This bloody thing was supposed to be cheap and easy. What fairy tail was I listening to?

I'm no electronics expert....but I've worked with guys who were board-level IC designers and I had to source surface-mount and through-hole components for them. So I learned a little about that stuff. Somewhere I remember seeing a multiplier chip (or something like that) that would create extra pulses from one pulse, for whatever reason. If I were you, TZ, I'd talk to anyone you know that's really into electronics at the board level. I'm sure they would be able to come up with something for you to integrate into your tach circuit.....and the bonus is that most of those chips are dirt cheap.

See if you can contact Phil C from England. He was on this board before it died, I don't know if he has re-registered for the new one or not. He helped me reverse engineer a CDI box for my GT500, been working great for almost a year now. The man knows his stuff!!!