The speedometer is from a 70’s era Yamaha Enduro (like an AT1 or DT1).
The SR250 didn’t have a tachometer and the engine is not designed to accept one. I used a Bike’s Choice electronic tach from Dime City Cycles.
The LED’s (yellow, blue, green) are from DigiKey.
How did you get the electric tachometer attached? I can’t figure mine out
I don’t recall if mine came with a wiring diagram or I found one on the internet. Here’s a video that describes how to hook up the wiring.