Tachometer issue

My 83 900 has a tachometer glitch that I've discovered now that I'm braver and exploring the upper revs.

The tach seems to work fine during "normal" driving, shifting at 4500-5000, it reads fine, but if you head north of 6000, it bounces around, seems to stick etc. If you hold the revs up at say 6500-7000, the needle settles down somewhat but if you add throttle it bounces around again.

Full throttle acceleration, the tach is completely inaccurate, I shift when I'm scared!

Obviously an electrical gremlin, there is absolutely no misfire or anything amiss that would suggest a coil/module issue.

I've read the forums, and there may be a rev limiter associated to this model but other than the bouncing needle, I've not experienced a misfire. I;m not sure I have the balls to go and see if there is a working rev limiter in my machine.

Thoughts?


Dave, 83 900

 

Hey Super,
I was looking into the 'Over revolution switch' from the XJ900 and found it was associated with the tachometer electronics inside the XJ900 dash.

Take a look at the pictures from 'Alive' in the thread

I did end up just leaving the over-revolution circuit disconnected from the TCI as I don't have a XJ900 dash, or wiring harness for that matter!

On another note... I've noticed that the tachometer needle is sticky on my build bike so it's like its stuck at 0. If I give it a flick it goes above and then sits at the right point when idling. I'm pretty sure its a lubrication problem with the actual needle bearing... I wonder if you have a similar sort of problem? Maybe a bit of a clean and a service?