Jumpy tachometer solution.

All right this may be a big help to a lot of people who install a vapor, koso, or digital speedometer.

I recently installed a universal eBay Chinese El Cheapo speedometer tachometer. And like many post I've seen on svrider and other forms there is a problem with the tachometer being very jumpy. I didn't find a lot of information except for a resistor seemed to be the common solution.

So I had to buy the pack off of Amazon that came with several hundred different size resistors. I had to continually add resistance until I found the sweet spot of around 3600 ohms. This is considerably higher than the others but I seem to have had a lot of crap or interference on the wire that I ran. I recommend starting off with three 200 ohm .25 w or 600 ohms like the other forms suggested, and then gradually increase until you find your sweet spot getting rid of the interference that you may have.

I connected my pig tail to the rear ignition coil white wire. Not to be confused with high beams wire. I tried the black yellow but the white wire to the rear ignition coil proved to be a better signal.

Small by -Ransome-, on Flickr

[R1ffR4ff]

Nice work and good to know

Any chance you could make a blow-by-blow of how you fitted and wired it just in case I ever need to replace my own on my Curvy?

Sure ill try to do that this weekend.


One more tip I forgot to mention, if you get the cheap resistor pack from Amazon or ebay, be sure to meter each resistor. some of mine were a dead short.

[R1ffR4ff]

Originally Posted by Jacobus

Sure ill try to do that this weekend.


One more tip I forgot to mention, if you get the cheap resistor pack from Amazon or ebay, be sure to meter each resistor. some of mine were a dead short.

Good stuff