Author Topic: Tach Suddenly Reading 7K  (Read 2214 times)

Offline Kiwi_Roy

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Tach Suddenly Reading 7K
« on: March 01, 2015, 06:26:16 AM »
The tach on my EV decided to read 7000 today even when off, is that the counterweight issue?
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Online PeteS

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Re: Tach Suddenly Reading 7K
« Reply #1 on: March 01, 2015, 06:55:45 AM »
If it stays at 7k when you move the bars back and forth its probably the counterweights. If the needle flops around its a broken support spring. You can try to fix it but its not easy and its almost impossible to make it read correctly again. Best to bite the bullet and get an aftermarket replacement.

Pete

Offline Strom

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Re: Tach Suddenly Reading 7K
« Reply #2 on: March 01, 2015, 07:07:01 AM »
Broken springs usually get broken at the soldering point. It can be fixed with not much trouble, the biggest problem being able to open it up (and put it back together - glass tends to crack. Get a backup glass or plexi).

I was able to fix mine 2-3 times before it died completely. Looks like the coil thing went - not sure.

I like the looks of the original dash, so.... searching for a cheap working replacement and hope it will work for a few years.
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Offline Caffeineo

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Re: Tach Suddenly Reading 7K
« Reply #3 on: March 01, 2015, 08:09:34 AM »
I had one of the weights come off and the tach just hung out around 1K, running or not. Found a thread on here with some pics of how to take it apart and was able to get the weight glued back on and everything back together without breaking anything.  ;-T Now the tach works but reads about 500 low. Just happy it still moves as I really like the original look and would not stick anything else in there. You may also search for a speedometer/instrument shop to fix it.
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Re: Tach Suddenly Reading 7K
« Reply #3 on: March 01, 2015, 08:09:34 AM »

Online PeteS

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Re: Tach Suddenly Reading 7K
« Reply #4 on: March 01, 2015, 08:43:16 AM »
Sometimes the weight just shears off, othertimes it vibrates to dust at the bottom of the can. Thats what happened to mine. I had to guess at the weight and glued a piece of lead in its place. I then recalibrated it with a pulse generator. Somewhere inside you will find a sticker that says either 5500 impulsi (sic) or 11,000 impulsi depending on which model its for. That is the number of impulses for a full scale reading. My mistake was calibrating it with the dial laying horizontally. I should have done it at the angle it sits on the bike. Mine always read high after that and I knew if I pried the bezel off one more time it would have come apart.

Pete

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