MicroSquirt.com read only forum (Jan.15,2018)

If you have a Hall sensor, you could use the leading edges for a 'Basic Trigger' arrangement. There is an experimental patch for the MS2/Extra code that needs an adaptor circuit that allows that pattern to be used with a VR sensor, but otherwise that wheel cannot be used with a VR sensor or for ...

Looking at your pic, the wiring is incorrect. The uS pin VR1+ is not used. The +ve side of the VR sensor goes to uS pin VR1- (diode band towards the uS); the -ve side of the VR sensor goes to uS GND (diode band AWAY from the uS).

Some of the pins are labelled "Power GND"; there is also "Sensor GND" and "Serial GND." Just rechecking the schematic, all the ground pins are tied together at the circuit board, so it doesn't particularly matter.

Ok, I did mention an edge detection circuit, not just wiring the sensors directly to the uS ...

Try this:
Sensor 1+ to diode (band towards uS) to VR1-
Sensor 1- to diode (band away from uS) to power GND

Sensor 2+ to diode (band towards uS) to VR2-
Sensor 2- to diode (band away from uS) to power ...

How exactly do you have the 4 wires from your two VR sensors wired?

I'm not familiar enough with the B&G code; I'm more able to comment intelligently on the Extra code. It strikes me the offset for #2 cyl should be 180, not 0. I have no idea why you're getting a "too many teeth before missing tooth" error when you have NO missing teeth!

The problem is that the VR circuits used by the MS family are all zero-crossing triggers, and while they are extremely accurate with closely-matched tooth / sensor combinations, they are notoriously unstable with mismatches; the bigger the mismatch, the greater the instability.

For the Yam TCI box ...

Time for a pic ...

Are you sure? I acknowledge all the example are -1 or -2, but there's nothing to say there's a limit. TS doesn't seem to have a restriction.

The old MS1 was restricted to -1 or -2 ...

You MAY have a ground loop. You mentioned MS to frame, frame to engine, frame to battery. There may be a heavy engine to battery for the starter; if so, you can have weird things happen. The preferred grounding scheme is MS to engine, engine to battery, and leave the frame out of it.