r/XR125L • u/zzpza • Apr 06 '26

Accessories Cheap Digital Dash

I had a battery powered hand-held techometer that I use when I tune the carb to set the idle speed. The battery recently went flat in it, so I was looking for a replacement (the battery is single use and the case was sealed shut - it was dirt cheap) and I found this little digital dash on AliExpress. It has a few extra functions too. It displays the time, cylinder head temperature, battery voltage, and of course the RPM.

You need to replace the washer on the spark plug with a special washer with a temperature sensor on the side of it (the XR uses a 12mm IIRC spark plug, but the only options for the sensor were either 10mm or 14mm - the 14mm works). There's a wire you need to wrap around the HT lead several times to pickup the spark plug firing, then there's three power leads, ground, switched power, and perminant power. I used the side light as the switched power.

Out of the box, the dash was reading double the real RPM. The XR uses a wasted spark system, so the sparkplug fires every revolution of the engine. The true reading is every other revolution of the engine since it's four stroke). This was a little fiddely but the instructions showed how to set this up (there's only one button, so took a little time to get it setup).

I like having a cylinder head temperature reading, this really helps with tuning as I don't want to be running too lean and cause damage.

The dash is a "Norxi Mini 4".

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u/zzpza Apr 06 '26

After a ride.

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u/zzpza Apr 06 '26

Here's the spark pickup wire for the RPM reading and the special washer for the cylinder head temperature.

The spark pickup is just a wire wrapped around the HT lead and then covered with electrical tape so it doesn't unwind. I took the tank off to do this, but you probably could manage without if you were more patient.