Tachometer not working

Message

malibu55 · #1 Post by **malibu55** » Wed Apr 30, 2008 1:32 pm

I am getting my '85 RZ500 (Cdn.) back on the road after sitting in my garage for 15+ years. It only has 6000 kms on it and is in excellent condition. I have re-built the carbs and all that stuff and it started up and seems to run great (no road test yet as front brake needs bleeding).
The tach however is motionless. It never malfunctioned previously.
Any suggestions out there? Bad ground, etc.?
The rest of the cluster is working fine....temp gauge, idiot lites, etc.

Matty · #2 Post by **Matty** » Thu May 01, 2008 3:12 am

What's your battery like?
I think the tacho needs more power to operate than the instrument lights so the tacho drops out first.

malibu55 · #3 Post by **malibu55** » Thu May 01, 2008 8:30 pm

Thanks for the reply.
My battery is brand new. What sends the signal to the tach?....a sensor on the cdi unit?...YPVS control box? I'm thinking it is a bad connection somewhere like that but I don't know the circuitry or how the tach actually works.

Mike Cichetti · #4 Post by **Mike Cichetti** » Fri May 02, 2008 8:52 am

Sometimes when the bikes sit I've found that the tach binds or gums up. Take it for a decent length ride, making sure the battery is good and you just may find it will slowly come back to life. I think they jus tget stuck from sitting in some cases. After 40 or 50 miles it may be fine. Good Luck!

malibu55 · #5 Post by **malibu55** » Sat May 03, 2008 11:27 am

Thanks Mike. I'll try that technique. I am sure you're right.

malibu55 · #6 Post by **malibu55** » Thu Jun 05, 2008 11:33 pm

Mike,
I just did a short test ride today and sure enough the tach needle started creeping up the scale as I drove along.......not following the revs up and down but rather increasing and staying high.

As soon as I returned home it slowly started to return to zero....within a few minutes it read zero again. So, I am confident your advice is right on....it just needs a little more work and some summer heat.
I will advise once I get more miles on her.

malibu55 · #7 Post by **malibu55** » Sat Jun 21, 2008 8:56 pm

Mike,
I now have about 60 kms (36 miles) on her and I am happy to report the tach is following the revs up to approx 4k. I am sure it will come around very soon.

Mike Cichetti · #8 Post by **Mike Cichetti** » Sun Jun 22, 2008 1:12 am

Glad to hear it's working.

malibu55 · #9 Post by **malibu55** » Sat Jul 05, 2008 11:25 am

Mike,
My tach is now fully functional after 100kms.
Thanks again.

Glenn

PilotMarky · #10 Post by **PilotMarky** » Sat Jul 18, 2015 4:15 pm

I have the same problem. Bike stood for 25 years. Hopefully mine fixes itself after a bit of riding.

Mike Cichetti · #11 Post by **Mike Cichetti** » Sat Jul 18, 2015 8:34 pm

Just give it some miles and see what happens.

PilotMarky · #12 Post by **PilotMarky** » Tue Sep 08, 2015 10:15 pm

Yep! Working perfectly now after similar number of km!

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