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Speedometer problem


SILVER-SURFER7

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SILVER-SURFER7

I was heading home last night, about a 70 mile ride, was in sixth gear doing about 70mph when my speedometer needle started jumping back and forth between 50 mph and 80mph.

 

It did this for about 5 miles, kept the RPM constant, was doing 70 the whole time, no drop off in power just the speedo jumping around. Then it went back to normal for another 10 miles. Speedo jumped around again for another mile, then was normal rest of the way home.

 

2004 R1150RTP, loose connection at speedo-speedo wearing out? Anyone have similar problem?

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If you haven't rewired your HES, you might want to check it. Sometimes it will cause the speedo to jump around.

 

My speedo cable broke at 63k. No warning. Just stopped working.

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Same thing happened to my '03RT. Tried cleaning & lubing the cable-cheap fix if it works-didn't for me. New cable didn't work either. Found a good deal on a new RTP speedo on ebay ($100). Works great and I really like the improved accuracy.

 

Speedo shop wanted $250 to set the odometer-I didn't go for that.

Edited by TheOtherLee
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The HES will not cause this problem on a R1150RT since it has a mechanical speedometer.

 

Also, the HES has nothing to do with the speedometer on any bike. It's the tachometer that could be affected.

Edited by kioolt
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.....

when my speedometer needle started jumping back and forth between 50 mph and 80mph.

......

 

2004 R1150RTP, loose connection at speedo-speedo wearing out? Anyone have similar problem?

 

When my 03 did this it also made a loud squeal.

I changed the cable & it stopped....... for too short of a time, then returned.

 

I had read that the bushing in the speedo gives out & the only thing to do is to replace the speedo.

Apparently you don't lube this bushing as it can contaminate the speedo.

Thought about that a bit and determined that it was silly worrying about contaminating something that should be tossed anyway.

I tore the dash apart & removed the speedo.

Packed the bushing with Lithium grease & reinstalled it.

It's quite as can be after 10+k & no contamination occurred.

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My 04 used to do this if I went over 140kmh. It would stop if I stopped the bike and let the speedo go back to 0.

I removed the core of the cable, cleaned and re-greased and it has been fine ever since.

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On a mechanical speedo, inside the speedo, there is a small steel cylinder attached to the end of the cable from the tranny. Inside this cylinder is a very slightly smaller magnet (close tolerances) that is attached to a tiny shaft with the speedo pointer (or "hand") on the other end. Also on this tiny shaft is a very small coil spring, small end attached to the tiny shaft, large end fixed to the speedo frame. This spring can be adjusted to correct the speedo, or to get you out of a speeding ticket.

 

The odometer is a separate set of gears and counter driven by the incoming cable from the tranny. If it stops, it usually means the cable failed.

 

An electrical (non digital) speedo will have a coil in place of the steel cylinder.

 

Several things can cause the pointer to go crazy:

If the cylinder touches the magnet, the pointer goes crazy. This can be caused by either the cylinder bearing or the magnet/shaft bearing wearing out.

 

If any small particles get between the cylinder and magnet, the pointer goes crazy.

 

Also on the tiny shaft somewhere is a pot of light grease that acts as a dampener to the pointer, so that it is very smooth in operation. If this grease gets old or displaced, the needle will typically vibrate slightly. Probably not your problem.

 

Some types of speedos can be rebuilt, some cannot. Finding a shop, parts, or someone that can do it is another thing.

 

Probably time for a new speedo. Sorry.

 

Good luck.

 

 

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I was heading home last night, about a 70 mile ride, was in sixth gear doing about 70mph when my speedometer needle started jumping back and forth between 50 mph and 80mph.

 

It did this for about 5 miles, kept the RPM constant, was doing 70 the whole time, no drop off in power just the speedo jumping around. Then it went back to normal for another 10 miles. Speedo jumped around again for another mile, then was normal rest of the way home.

 

2004 R1150RTP, loose connection at speedo-speedo wearing out? Anyone have similar problem?

 

Your speedometer issue is pretty typical of an older mechanical (cable driven) speedometer when the weather starts getting colder.

 

As a rule it is due the to the inner speedometer cable (the woven inner cable) winding up then jumping forward on each revolution due to being dry or having old dried out grease.

 

You speedometer is driven off the front wheel with a woven metallic inner cable within a stiffer outer sheath. That inner cable must be able to drive the speedometer magnetic head with a very smooth input (if the input isn't smooth then the speedometer needle starts jumping around)

 

In most cases you can get your speedometer back to running smooth again by unscrewing the lower cable attachment ring (at left side of front wheel) then pulling the outer/inner cable out of the drive. Then pulling the inner cable out of the outer cable sheath.

 

Once the inner cable is removed then you can clean it of old dried grease & crud by using WD-40 or mineral spirits.

 

Once the inner cable is clean you then inspect it for wear & fraying.

 

If the inner cable is in decent condition then you can simply re-grease it with proper speedometer cable grease, or a cold weather grease like white Lubriplate grease-- (in any case DO NOT use standard chassis grease or other thick grease as thick grease can break the inner cable in cold weather or cause excess loading on the drive/driven gear unit --Speedometer cable grease or white Lubriplate is usually available from a local auto parts store.

 

When greasing the inner cable don't over-grease it & don't grease it all the way to the top of the cable (stop about 2" short of the top. Or, if you do grease it full length then be sure to remove as much of the grease as you can from the top couple of inches.

 

(Important)- If the top couple of inches of inner cable have too much grease that grease can migrate into the magnetic drive area of the speedometer head & really gum it up.

 

My guess is: a good inner cable cleaning & proper re-greasing of the inner cable & your needle oscillations will disappear.

 

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I had the exact experience three years ago on a trip out west. I posted on this site to see how much aggravation it would be to change the cable at roadside and the reply (sorry I don't remember who, maybe the rubber chicken guy) directed me to the speedometer drive on the left side of the front wheel.

 

The metal drive tang in the front wheel hub spins a plastic sector disk in the speedo cable drive unit. Over time the two drive tangs wear through this disk and the speedo skips around while it wears a clean groove through it, then the speedo stops working entirely.

 

Sure enough, I pulled the axle and dropped the front wheel, removed the drive unit on the end of the speedo cable, and that is exactly what had happened. The groove through the plastic driven disk was easy to see The repair was quick too. Bend the two tangs out (towards the plastic part) about a sixteenth of an inch, reassemble and ride. It took about twenty minutes total outside of the motel room and that drive unit is still spinning the speedo just fine three years and over 30K miles later.

 

The root cause is likely a stiff cable as that is what probably leads to the excessive wear on the drive disk. I had to replace mine about two years later.

 

Many thanks to the gentleman who gave me this tip. It's definitely worth a look before playing with the other bits.

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I had the exact same thing happen to me although my speedo just quit working. I did what you did and it has been working just fine for 3 years. Great fix for $0!

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  • 8 months later...

My speedometer just quit on day 3 of a 16 day trip. I was not happy about using the GPS for my speedometer. I found this thread and sure enough, bending the metal tangs on the wheel worked for me too. I could see where it had worn the plastic piece inside of the speedometer coupling.

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If you haven't rewired your HES, you might want to check it. Sometimes it will cause the speedo to jump around...

No it wont. Not in the slightest way are they connected.

However, you may have seen your tachometer 'jump around'. That IS a symptom of HES doom.

 

The OP also has a 2004 RT which is much less likely to suffer HES loom self destruction.

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