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Speedometer Question

Posted: Wed Sep 06, 2017 7:30 pm
by thumper580
The speedometer on my 85 RZ500 will go up to about 55-60mph and stop. The cable turns freely can't see anything out of the ordinary.. The needle just won't go any higher.

Any ideas?? Thanks.

Re: Speedometer Question

Posted: Thu Sep 07, 2017 4:27 am
by phildu31
You should check the drive in the wheel

Re: Speedometer Question

Posted: Mon Sep 11, 2017 6:25 pm
by thumper580
Phil, I replaced the speedo drive and still only 60mph??? It's not that complicated of a system...

Re: Speedometer Question

Posted: Mon Sep 11, 2017 7:43 pm
by tacky1
thumper580 wrote:Phil, I replaced the speedo drive and still only 60mph??? It's not that complicated of a system...

Try a different Gauge then, It must be that,
Did you pull the drive cable out of the speedo cable, These sometimes snap in the middle and can snag and drive the speedo a little.

Re: Speedometer Question

Posted: Mon Sep 11, 2017 10:56 pm
by thumper580
Tacky...I'll check the cable, but I'm pretty sure it is still in one piece. Another gauge set will be a little pricey...

Re: Speedometer Question

Posted: Mon Sep 11, 2017 11:13 pm
by tacky1
You dont need the set, just the speedo, Even to borrow a speedo, Any speedo will do as long as its mechanical, It doesn't have to be a Yamaha or for a 16" wheel. Its just to test that it goes over 60mph

Re: Speedometer Question

Posted: Tue Sep 12, 2017 12:31 pm
by thumper580
tacky1 wrote:You dont need the set, just the speedo, Even to borrow a speedo, Any speedo will do as long as its mechanical, It doesn't have to be a Yamaha or for a 16" wheel. Its just to test that it goes over 60mph
Thanks again... do you happen to know if the rz/rd350 speedo will work?

Re: Speedometer Question

Posted: Tue Sep 12, 2017 8:49 pm
by tacky1
They will work, but im not sure if the speed will read the same, I know the FZ600 works also, But the faces and needles are different as well, The RZ has a 16 wheel with a large, high wall tire, So it might read the same as the 18" wheel on the RZ350 F2 mode.

Maybe someone can chime in on this to be accurate, I have used FZ600 clocks and RZ350 F2 clocks for parts, But I used the RZ500 innards with them..

Re: Speedometer Question

Posted: Wed Sep 13, 2017 1:00 pm
by 2smoke
The ratio in all those clocks are all the same. And I believe all Japanese makes use the same ratio
So they will all work.
Its the speedo drive that has to match the wheel size.

Re: Speedometer Question

Posted: Wed Sep 13, 2017 3:26 pm
by silverstrom
The RZ350/TZR250 speedo uses a different scale than the 500 speedo. If you look at where the numbers are on the face you'll see they don't line up. The higher you go, the more the offset.

Re: Speedometer Question

Posted: Wed Sep 13, 2017 3:53 pm
by phildu31
Well, it should be just a test and try with another speedo if you have one.
Accuracy of the speed indication is not required, it's just to check if speed indication stops near 60mph ~ 100 km/h.
In 6th gear, speed is near 20-22km/h / 1000 rpm.
If speed indication goes linearly with rpm with no stop, your speedometer is out of service and you'll have to find a replacement one.
If still not, default is pretty sure in the drive mechanism.

Re: Speedometer Question

Posted: Wed Sep 13, 2017 7:13 pm
by Ron57
Hi get a drill and attach to the bottom of the speedo cable put into reverse should be to
see if it 's working properly.
Cheers Ron.

Re: Speedometer Question

Posted: Thu Sep 14, 2017 12:32 am
by silverstrom
It's difficult to get enough speed to make 60 MPH with an electric drill. 50 MPH seems to be the max I can get to here when testing. If you have a dremel tool that will run in reverse you may have more luck. I tried a pneumatic drill last week and it wasn't as good as I'd hoped.

I've found all sorts of insect life inside speedos. Try blowing some compressed air inside the cable receptacle. You can also use a few drop of WD-40, but make sure you don't get it above the dial face. I fixed a sticky RZ500 speedo that way last week.

Re: Speedometer Question

Posted: Thu Sep 14, 2017 10:43 am
by 2smoke
I believe all Japan made cable driven speedometers are calibrated to show 60 mph at 2240 revolutions of the speedo cable.
So those 2 different faces would have different calibrations inside?

Re: Speedometer Question

Posted: Thu Sep 14, 2017 9:11 pm
by silverstrom
2smoke wrote:I believe all Japan made cable driven speedometers are calibrated to show 60 mph at 2240 revolutions of the speedo cable.
So those 2 different faces would have different calibrations inside?
That is my understanding.