Speedo & Tacho sensors

[GSXKING]

I read with interest a recent comment about Speedo pick up which I will investigate soon.
Do any of you have an idea how the bike reads tacho information ? Hopefully the easiest explanation as I'm not very mechanically minded.

[Hooli]

It's probably from the crank sensor rather than a dedicated pick up.

[Eric GSX1400K3]

I need to review the wiring diagram, but I think tacho is read from the timing plate side (rhs), the same signal that determines firing of the plugs and injector timing.  Makes sense to me as this is the most direct revolution counter.  The other likely one is the speedo sensor on the lhs, as per the post about the "mystery mileage" by Mr. Gee.

Both have a 4 tooth sprocket, and both use a hall-effect sensor to detect magnetic field disturbances or pulses which get converted to voltage signals for the ecu.

[grog]

Tacho gets it signal directly from ECU which gets its signal from crankshaft position sensor,under rh engine cover.How to test and wiring colour ill look into.