Vintage Dirt Bike Q & A

On a 1975 MT125, has anyone atempted to use the CR125 CDI ignition and still keep the MT lighting and charging coils?
This would allow me to run the MT lights and charge the battery and have the hotter spark of the CR's CDI.
Thanks.

I looked into this briefly when upgrading my MR to the CR ignition. Since the CR CDI rotor and stator must be used as a set, I don't see any way to provide the standard MT lighting/charging system with sufficient power, and the PVL CR125M aftermarket ignition doesn't include a lighting coil.

You might consider LED lighting. It would be fairly easy to make custom LED bulbs using burnt-out bulb bases and high-intensity LEDs, if they're not available off the shelf. You could power them with a small gel cell as used in house alarm systems. A simple low-current charger (diode and resistor) supplied by the stator pulse coil would charge the battery up when the lights are off, with the battery supplying the lion's share of lighting current with the lights on. Twenty 20mA standard LEDs should run for at least 2.5 to 3 hours off a 1.2 amp-hour gel cell, and 2mA low-current LED's are available too. I can supply component values and procurement info if you're interested.

For what it's worth, I've never missed having lights at all, and the instant response of an MR or MT light-crank motor with the CR ignition is really cool.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric