tach guage needle barley moves ?

it moves but barley ?

 

Running, Cranking or What?

 

Pull the Instruments and take-out the tach.
Look at the back of it.
There's a Brass Bearing Bushing
Clean it with alcohol
Carefully "Flick" the indicator as you do.

Put 1 (One) drop of WD-40 on it.
Move the Indicator Needle a few times.

 

thanks Ill try that .

 

I have this very same issue on my 82 XJ750J. I decided to crack open the instrument panel and take out the tachometer but I couldn't figure out how to get the tach out of the panel to perform the maintanance. I'm sure i'm just missing something very simple - Any suggestions?

 

You have to remove the cover and undo all the screws.

You have to undo the screws that the wiring harness attaches to the back of the Tack; too.
Mark them or make a drawing.
Once the wiring harness is removed there are two mounting screws to release and the instrument comes out of its bezel.

 

Thanks for the info as I was able to get the tach out by taking the 3 screws that held the Black, Grey and Brown wires to the back of the tach. I then cleaned the back of it with alcohol (it looked clean as a whistle even before I started) while flicking the indicator a couple of times. I then put one drop of WD40 in there and flicked the indicator once or twice more. I then put everything back together and started up the bike. In idle, it still barely moves when I rev up the engine with the throttle. Does the bike have to be moving down the road for the tach to work?

NOTE: I am still having issues with the blinkers, horn and LCD warnings not working. - This all started the same time my tach stopped working.

 

The tach started to work (along with everything else) when I decided to solder the connections to the blade-style fuse box instead of using crimped on connectors.

 

Corrosion strikes again! You have been throughly initiated now, welcome to the club.

 

I had the same problem with mine a few years ago when i pulled the bike out of it's 15 year resting spot in the woods. I was pulling my hair out trying to figure out why the electrical systems were working poorly. Turned out to be a corroded ground! Sometimes we get so involved with the complexity of the system that we forget about the simple things we need to check first.