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View Full Version : Jumpy tachometer solution.


Jacobus
20-03-18, 11:05 PM
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.

https://farm1.staticflickr.com/788/27047496988_2e894dc8fc_b.jpg (https://flic.kr/p/Hd6uwY)Small (https://flic.kr/p/Hd6uwY) by -Ransome- (https://www.flickr.com/photos/87232521@N02/), on Flickr

R1ffR4ff
21-03-18, 02:29 PM
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?

Jacobus
22-03-18, 02:00 AM
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
22-03-18, 09:38 AM
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 :)