Crazy speedometer

[Burque73]

I know the gauges on these bikes are a bit jumpy but this is quite distracting. Seems to be getting worse too. Anyone have this issue? What did you do to correct it?

[posplayr]

Take the gauge apart and clean the gauge. You can try lubing the cable first. Pull it out and clean and regrease.

[Brendan W]

Cable first suspect. Because it's so long it can twist quite a bit if it's dragging even a little.
It's the rotary equivalent of compressing a spring and when the stored energy gets released it provides an impulse or step input to the speedo.
Then depending on the speedo spring and the size of the step the needle will swing around the actual speed.
It could also as Jim points out be in the speedo itself but before opening it try using moderate amounts of lube at the cable input first.
Fairings make the soundscape a bit tricky but sometimes a dry cable will hum.

[Steve]

I had a tach that did the same thing. Replaced the cable (with OEM cable), now it's rock-steady.

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[Burque73]

I'll pull and lube or just replace the cable then.

Thanks for the replies.

[posplayr]

I had a tach that did the same thing. Replaced the cable (with OEM cable), now it's rock-steady.

.

Must be that the inner Teflon liner wears through.

[posplayr]

Cable first suspect. Because it's so long it can twist quite a bit if it's dragging even a little.
It's the rotary equivalent of compressing a spring and when the stored energy gets released it provides an impulse or step input to the speedo.
Then depending on the speedo spring and the size of the step the needle will swing around the actual speed.
It could also as Jim points out be in the speedo itself but before opening it try using moderate amounts of lube at the cable input first.
Fairings make the soundscape a bit tricky but sometimes a dry cable will hum.

nice analogy on the impulse response of a high q system.
with a second look I can better visualize the cable windup releasing and kicking the needle. I recall putting a lot of grease into cable once and it not having a lot of effect, but if the inner liner is worn through then who knows.

[jorgeno]

Looks like it’s about to brake down. Open it up and lube or else it can be like this:

[bwringer]

My GS850 is at 128,000 miles and the bushing where the speedo spinnamathingy spins is just plain worn out. It jumps around like this as it flops around. If I lube it, it'll go back to normal for a while but then it reads 30% high. I've had it apart a few times, but I think I'm out of options.

I really need to head down to CRC2 and scare up a replacement soon.

[LAB3]

Mine was doing that so I sprayed it with silicone through the hole that the light mounts into. This worked OK for about 1000 miles then it would start again. After doing it a couple more times and seeing the same result, I cut it in half with a hacksaw and gave it a good cleaning up with rubbing alcohol then lubed it with 3 in 1 oil. Hasn't missed a beat since! Don't get the alcohol on the dial face, mine got a tad on it and it ate right through

[roeme]

I'm currently teaching myself and researching which skills are needed to create replacement gauges that are to my liking - I don't like the tiny cheapo cafe racer replacements, and digital ones are flat out wrong on these bikes, and look tacky anyway. Life keeps interrupting, though.

[Burque73]

My GS850 is at 128,000 miles and the bushing where the speedo spinnamathingy spins is just plain worn out. It jumps around like this as it flops around. If I lube it, it'll go back to normal for a while but then it reads 30% high. I've had it apart a few times, but I think I'm out of options.

I really need to head down to CRC2 and scare up a replacement soon.

Son, do you know how fast you were going?

Actually sir, due to this 35 year old spinnamathingy I'm 70% sure I was only doing 55.

[Brendan W]

The numbers on the tacho are easier to see. That's my speedo.

[dennco2]

My speedometer started to jump around too ... plus it started to make a howling noise intermittently. I pulled it out of the instrument panel and opened it up and lubed/WD40 all rotating mechanisms. Problem solved and the needle is very steady. Previously, I had cleaned and lubed the drive cable.

[bwringer]

My GS850 is at 128,000 miles and the bushing where the speedo spinnamathingy spins is just plain worn out. It jumps around like this as it flops around. If I lube it, it'll go back to normal for a while but then it reads 30% high. I've had it apart a few times, but I think I'm out of options.

I really need to head down to CRC2 and scare up a replacement soon.

Replacement obtained today. It took Rob a good bit of rummaging around to find two possibilities.

My GS850 is currently wearing an older orange speedo from some unknown GS. No reed switch for the auto cancelling turn signals, and it looks a little different, but it fits and works well (reads the usual 7% or 8% high compared to GPS, works smoothly). $20. I can live without the auto-cancel turn signals for a while; my other bikes don't have them.

I also have what appears to be an exact replacement, with the white plastic body and the reed switch. However, one of the screws holding the face on is bouncing around inside. Not a big deal -- I've mastered the art of opening these without damage -- and I'll fart around with it sometime when it's cold and wet outside and I'm bored. He let me have it for $5.

I'll also keep track of the mileage, and I may be able to set the odo on the replacement correctly. I've figured out how to do it on a junk speedo, but it's a rather delicate operation.

It's nice to work 20 minutes away from Cycle Recycle II. That place is a national treasure.