two stroke carb swap tach signal

[two stroker]

Hello I just got the new microsquirt 3.0 , using for fuel only my engine is a 2cyl 2 stroke one coil and two wires sort of a wasted spark, i was gonna go off the neg of coil for signal but my coil pulse twice per rev , will this matter ,will the ms think im reving twice as fast. thanks

[dontz125]

Are you running a CDI or a TCI ignition? A lot of 2-strokes run CDI, and the high voltage isn't really healthy for the circuits.

By setting the injectors to fire alternating, you will get one spray per injector per rev, which sounds about right to me ...

[classic-indy]

I'm also running a 2 cylinder 2 stroke. When set to 2 stroke it will read true rpms of the motor not 2x. Currently running a fly wheel which has 2 teeth of equal length. Because of this my ecu doesn't know where each piston is @ therefore I used 2 squirts per revolution.

Anyways. Hope this helps. I also found that 2 sequential squirts each revolution helped with smoother running in addition to it easier starts!!!!

[classic-indy]

oh also it was a little more work but I used a hall sensor on the flywheel, with a (470 ohm?) pull up resistor using the 5V vref I then drilled and tapped the case above the flywheel. Much better than a GMR sensor in my opinion. I burnt out my GMR sensor after about 15mins of run time, which sort of tainted my views on GMR's.

[two stroker]

Thanks for the info. My sled is a 2010 summit 800r ,the carbs had a tps for the ignition so i have to use it ,can i just tap into the signal wire for the ms or do i run another tps just for the ms . i turboed this sled last year, ran great but a pain to jet so im upgrading to a 2871 ballbearing turbo and fuel inj, hope it works, thanks