RPM in the Motec software wrong

[Dreher7]

Hey Folks,
I might need your help, as I cant think anything else to do it.

I have a single cylinder engine, with no cam shaft sensor. The engine is not attached in the dyno engine.
The problem that i am facing is:
In the software, the first gauge which shows the RPM, the readings are way too high, looks like is double that what must be, but that is just a guess.

Following the orientation of motec dealer, I have set up the number of cylinder as -1:


Here is my REF/SYNC set up:


I don't know what else I can change, or try to get the RPM readings correctly. The engine has 10 teeth, missing one.

Ref/Sync file:
https://github.com/g4Iv0t4/Motec_HYD/blob/main/firstAttempCrankSensor.rsc2

ECU File:
https://github.com/g4Iv0t4/Motec_HYD/blob/main/First_test_afterAdjust.e35

Any suggestions?

[Stephen Dean]

Looking at the RefSync capture this looks like it is a four stroke engine. If so, then the number of cylinders needs to be set to 1, not -1.

[Dreher7]

Hi Dean,

The decision to put 2 stroke it was because the engine hasn’t got a cam shaft sensor. So it was reasonable assumption..
That was the only way to get this engine working

[David Ferguson]

Have you considered using a MAP signal for the sync. Works really well for single cylinder engines.

[Dreher7]

Have you considered using a MAP signal for the sync. Works really well for single cylinder engines.
David Ferguson
Veracity Racing Data

Do I just need splice the signal from the Map signal and send to the SYNC pin in the ECU?

Thanks

[David Ferguson]

Yes, splice the MAP signal to the SYNC input. Configure as a magnetic sensor, then run a Ref/Sync capture to determine an appropriate trigger voltage and edge. For example, on a KTM 450, I trigger at 2.1V, Falling Edge.