Tach goes to 10000rpm when bike is switched on

[James]

The tach on my Classic goes to 10000rpm and stays there when the ignition is switched on (not started). Where should I start to look when trouble shooting?

[James]

photos

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[Anthony Duffield]

James,

I do not know enough about the aircooled bikes to be of assistance, JB on this forum has a lot of experience, if you cannot find him with a search let me know.

Tony

[Anthony Duffield]

James,

Search for johnbirchjar, you will be able to send JB a private message.

Tony

[James]

one clue that will not go away is the tach malfunction, with the key on, I unplugged each connector in the wiring harness one by one. It did not change with all the connectors unplugged, so it has to be the tach or the binnacle wiring, visibly it seemed good.

[James]

Can I replace my tach with this one from Andover Norton? They do not know. the backs are different
https://andover-rotary.co.uk/rt/shop-de ... ram-dryfix

an my tach compar.jpg

[draxdave]

HI, I have two MotoMeter Tacho's, middle and RHS, and a Made in France, LHS, numbered 0980 091 9900 (?)

I could send you one to try if you like ?

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[James]

thanks for responding, I have sent you an email, again thank you very much

[James]

I disconnected the black/white trigger wire from the tach, reinstalled the binnacle, turned on the key and the tach still goes to 10k, which tells me its in the tach, I found someone that will rebuild/repair it here in the states, so more to come

DSC04710 my tach underside.jpg

[James]

Also the tach still reads 10k while running

[johnbirchjar]

Hi James,I never had any problems with the tacho on my Classic,so unfortunately I cannot be of any assistance,sorry,seems like you are getting help from our forum,good luck,hope you get it sorted, ride safe,J.B.

[James]

Thanks for the response, I have found someone in the states to repair it, as I believe I have isolated the problem to the tach itself, also the speedo trip odometer reset does not work.

[johnbirchjar]

Hi James,
Re:the speedo trip metre,
The one on my Classic stopped working very early in the bikes life,almost impossible to repair(so I was informed at the time)finances at the time were a bit limited so I managed to live without a trip metre , I got so used to not having one that I never did bother,J.B.

[James]

Hi James,
Re:the speedo trip metre,
The one on my Classic stopped working very early in the bikes life,almost impossible to repair(so I was informed at the time)finances at the time were a bit limited so I managed to live without a trip metre , I got so used to not having one that I never did bother,J.B.

We will see if the person I sent it to can tackle it

[James]

I disconnected the black/white trigger wire from the tach, reinstalled the binnacle, turned on the key and the tach still goes to 10k, which tells me its in the tach, I found someone that will rebuild/repair it here in the states, so more to come




DSC04710 my tach underside.jpg

Here's something very interesting and is hard to explain, the black/white wire going to the tach is "hot" all the time regardless of the key position when the bike is not running.