MVT DD12 ignition conversion

[vforce94]

Hello everyone,

I have recently started a project on my Aprilia RS125 and custom fitted MVT DD12 scooter ignition. 

Here is the deal:

- I have machined the magnet to fit the flywheel,
- Also i have machined custom backplate to fit the stator,
- Created a custom single phase rectifier for the ignition,
- Adapted all the wiring to fit the custom ignition.

The problem lies within the signal coming from the stator. There are four wires coming from the stator, Yellow and white wires with fast-on connectors shoud be lighting coil output, Yellow-geen wire with circular fast-on should be the ground wire and Red-black wire is excitor coil i guess?

Could someone with knowledge about DD12 ignition help me with this engima since I don't have another scooter to measure the ignition output signal. What type of signal is coming from the Red-black wire ?
Also, depending on the wire output, what could be done to convert the signal to the inductive signal like gnitions with external pickup ?

Thank you very much for your help in advance.

P.S. Here is an image of the ignition wiring for the reference. 

[90GTVert]

Here's what each wire does when tested with a multimeter :
youtu.be/buUEmdHxxXY

[vforce94]

Hey, thanks a lot for the video, do you maybe know what voltage readings do you get at higer RPM because i need to build a circuit that will simulate the pulses up to 13000 RPM.

[vforce94]

Measurement is between Red-black and ground wire.

[90GTVert]

It took me a bit to get around to it, but I got you some numbers for exciter output at higher RPM today.

I managed to jam the multimeter probes into my sealed connectors and electrical tape and zip tie them to stay there. I set the meter to max volts and took a ride.

I stopped a few miles in and checked. 259V max. Seemed like roughly what I’d expect, but I reset it. When I did, the reading was low at idle so I had to fiddle with the connections and it came up.

Sorry some pics are upside down.



Back at it for a few miles and pulled over again. This time 305V.



Once more for good measure. Now 304V.



This was with max RPM of 14,300.

I looked at 2000RPM and that was roughly 100V. 4000RPM was around 160V. Prob doesn’t matter, but in case an idea of how it ramps up helps.

[vforce94]

Excellent, thank you so much. It is perfect. You have no idea how much you have helped me.