Instrument cluster maintenance

[aigram]

I've had a few issues with my instrument cluster over this riding season, and I was wondering if anyone has some ideas on fixing them:
1) My tach often gets stuck at 0 after the bike sits overnight. When I startup the bike, I more often than not have to knock on the gauge plastic window in order to "wake up" the tach needle. This used to happen occasionally, but now happens on 9/10 cold starts. It's gone from being a funny quirk on an older bike to quite bothersome.
2) My speedo cable backed it's way off the receiver end on the gauge cluster. Recently while riding, I noticed that my speedometer needle was jumpy. This bike actually has had a rock steady speedo needle in my time of ownership, so I thought it was odd that all of a sudden the needle became jumpy, but didn't think much of it. Then, I came to find out after a ride with no speedo movement that the cable backed off completely from the instrument cluster! Would the worm drive have hashed the mating gear inside the instrument cluster on it's way out? Is it safe to lightly use some thread locker (blue loctite perhaps) on the collar to prevent this from happening again? Related, does anyone lubricate each end of the worm drive cable?
3) My instrument cluster is quite rocky. When I ride over bumps, the cluster flops around quite a bit. I can also give the top or bottom of it a push and feel that there is a fair amount of play. It does not flop side to side, only up and down.

[T Legg]

I posted a way to lubricate the speedometer.
     https://fjowners.com/index.php?topic=19154.msg194494#msg194494
Having the cable come loose from the speedometer won't hurt it . The square shaft of the speedo cable just slips out of the receptacle.          
I haven't used it but a little blue locktite shouldn't hurt anything. I just use channel locks to tighten the cable a little more than finger tight .

[melloncollie]

I'll do my best here with my limited knowledge.

The tach I thought was relatively simple so I'd start with making sure electrical connections are clean and making contact.

Personally I wouldn't use thread lock because it might be a pain to take off later.  Though you could take the cluster completely out to get better leverage on the collar if you needed to take it off later and I can't imagine it'd hurt anything.  My understanding of the jumpy speedo needle is its often caused by a bad bearing in the cluster.  You can send it out to a place in Cali to get it fixed but sometimes lubing the cable and/or bearing restores it well enough.  YMMV

There are two rubber bushings/grommets where the cluster mounts to the bike.  The bolts are vertical so it allows the cluster to move (or kind of rotate) top/bottom but not side to side.  I don't think I'd describe mine as flopping though, maybe your bushings are bad or worn?

[red]

Aigram,

(1.) Is not something that I can help with, beyond guesswork.  My first guess is a bad signal connection or bad ground connection for the tach.  Your knock may be causing a better connection, which goes bad later when not in use.  In any case, a dedicated ground wire (going to a good chassis ground) is a good idea there.  Clean and re-install the various terminal ends inside the instrument cluster.  If you can remove the clear top cover, check that the tach needle itself works freely.
(2.) The cable end can not hurt the workings of the speedometer.  I would remove the cable core (from the bottom end, IIRC, then clean and lube the cable with a light petroleum grease.  Re-install the cable core.  White grease is not compatible with what is in there.  I would not use Loctite on the screw ends, but a small smear of RTV on the male threads will do the job nicely, without over-doing it.  FJ speedometer cables are still available, and inexpensive.
(3.) Sounds like some screws are loose or missing, or have broken through the plastic mounts inside the cluster.  ABS cement from the home-improvements store, or JB Weld, should make any plastic repairs you need.  You can dissolve some scrap ABS plastic (pieces of ABS plastic pipe) in a small cup of the ABS cement, to make a thick slurry that will build up any areas needing a stronger fix.
HTH.

[FJmonkey]

The tach issue could be an intermittent ground connection, the most common cause. Bumping the cluster suggests the issue there.

On the speedo, pull the cable and inspect for damage, a kink, broken strands, etc. Make sure both ends are secure/tight (medium strength thread lock will work if the threads are free from oil and grease (apply lightly, don't need it fouling the drive on either end. I used 2 cable ties behind the cluster. One just behind the nut with enough room to slip another tie in. The other tie gets secured near as possible to prevent the conduit from falling off even if the nut backs off. Get some lube designed for cables (I use Tri-Flow, PTFE/Teflon based, works in a pinch as cologne as well). If the needle is still bouncing, the problem might be age/mileage related. If so, it may later develop the "Strangled Cat Howl" and really bounce. Then its time to rebuild it or replace it. GPS speedos have been fitted with good results. A shop in San Deigo CA might still rebuild the older metric speedos, but time and low demand, pandemic might end this option.

The cluster is rubber mounted, if the mounts have decayed (inspection required), then time for new ones. But it will still wiggle by design.

[aigram]

Wow, thank you for the quick replies!
1) I would also think that it is highly likely that a bad connection is contributing to this behavior. I don't think I would have much luck in pulling connectors apart with the main fairing still attached to the bike. I really didn't plan on pulling it off this off-season, but it would definitely be easier to do some inspection of the harness with it out of the way. Can anyone point me to the connectors that I should be suspicious of? And especially where the ground is at? Also, with the plastic cover off, is it safe to use a plastic spudger tool to manually sweep the tach from 0 to redline-ish, in order to test if it's getting hung up somewhere?

2) When you mention cable core, is this the square (i.e. wormdrive) piece that spins inside the sheath/jacket of the overall cable? My speedo cable is actually only about 2 years old!

3) The bushings/mounts are also only about 2 years old. When I reinstalled them, I do wonder if I was not brave enough while tightening the two bolts down.

[aigram]

I posted a way to lubricate the speedometer.
     https://fjowners.com/index.php?topic=19154.msg194494#msg194494
Having the cable come loose from the speedometer won't hurt it . The square shaft of the speedo cable just slips out of the receptacle.          
I haven't used it but a little blue locktite shouldn't hurt anything. I just use channel locks to tighten the cable a little more than finger tight .

I read your linked post! Got a pretty good chuckle out of "When the speedometer hit 120mph..."

[red]

Aigram,

It helps us to help you if you put your year/model info into your signature or avatar caption.  Go here:

http://www.adeptpowersports.com/oem-parts/yamaha-parts.html

Pick your year, then select your bike, and look at the drawings for COWLING.  The entire cowling assembly attaches to the bike by just four bolts into a tubular framework.  Remove those four bolts,, remove two screws in the rear, disconnect the speedo cable and maybe a few other plugs, and the entire cowling can be pulled forward and flipped half a turn over, to gain access to things.  The "square shaft" is only square at the ends, and that is the cable core.  The wiring into the cluster is attached by separate screws, not just plugs, depending on what year you have.  If you see corrosion near any of the wires, that may be causing your problem.  Unscrew and check each wire for corrosion.  I would only move the tach needle far enough to see that it is free to move.  Loose hardware will become obvious, no sweat.  Your young speedo cable should be okay.  When the cowling is forward and flipped, you can cure the "howling cat" problem (if that is happening) by dripping some oil down into the speedo cable hole (not too much!).  No expensive instrument rebuild needed.  Did that trick for mine, and it has been quiet and normal for more than a year so far.

[aigram]

The model year and code is already in my signature

My speedometer cable continues to back itself off the threads on the back of the instrument cluster. This clearly needs some further attention in the off-season, but for now, I noticed a difference in the instrument-connected end vs. the wheel hub-connected end.
Is the instrument connected end missing a collar and washer piece? This speedometer cable was purchased a couple years ago from RPM. I've attached two pictures, one of the wheel hub end and one of the instrument end. Note that for both pictures, I simply slid the threaded collar out of the way for clarity; The cable correctly has two threaded collars

[red]

My speedometer cable continues to back itself off the threads on the back of the instrument cluster. This clearly needs some further attention in the off-season

Aigram,

If a smear of RTV on the male threads will not hold the speedometer cable collar in place, and you do not wish to use Locktite (I would not):
Hand-tighten the speedometer cable collar in place.
Then install a small hose clamp around the outside of the wayward collar, and safety-wire the hose clamp to some convenient anchor point on the cluster.
That'll fix it.  

[RPM - Robert]

Is the instrument connected end missing a collar and washer piece?

No, only one side has the collar and washer. I believe from the factory the collar was on the bottom. I install them with the collar on top at the gauge cluster and haven't had any reported issues from the 60 or so we have done here on FJs. Some people's mechanics will likely disagree and there may be some unforeseen issue on a single bike that can be noted from doing this. However, the reason I install them this way is, if for whatever reason you have a tire change, wheel off, balance or something of the sort and someone forgets to tighten the lower speedo drive side the inner cable will slide right out. Putting the collar and the washer at the top will keep the inner cable in the outer sheath. But then again the nut that spins on the speedo drive may be eaten up and unable to reinstall anyways if you ride too long with it flopping around.

As per your second issue of the cable coming off at the gauge cluster, have you tried uninstalling the cluster and tightening it? I always install them without removing the cluster but I haven't had an issue of them falling off either.

[ribbert]

My speedometer cable continues to back itself off the threads on the back of the instrument cluster.

Yes, they tend to do that. The fix is simply a matter of tightening it.

Undo the bolt holding the horn and let it dangle out of the way, you can now easily reach the back of the speedo with your hand and forearm. All it needs now is to be nipped up a bit tighter than you can get it by hand and it will never, ever come loose again. It does not need thread locker or mechanical securing.

Multi grips are the perfect tool for this. I don't know if they are called that in the US but this is what I mean......



Noel

[T Legg]

We call them channel locks over here Noel.

[red]

Multi grips are the perfect tool for this. I don't know if they are called that in the US but this is what I mean......
https://live.staticflickr.com/65535/52408555629_f492e4b67f_b.jpg
Noel

Noel,

In the USA, they are commonly called
slip-joint pliers.  They may have only two or three settings.
or
Channel-Lock pliers (same function, maybe a stronger mechanism).  Channel-Lock is a brand name.

[Firehawk068]

The original cluster that came on my 1990 had somehow developed a slightly "sticky" coating on the peg that the tachometer-needle rests against when the engine is off.
The tachometer needle would end up "stuck" to this peg, and would sometimes not move unless I tapped or banged on the cluster after sitting overnight, while revving the engine.
I have no idea how that peg developed a sticky coating on it, but one time when I had the cluster off I used some rubbing alcohol to clean that peg, and did not have that issue ever again.
This is the first thing I thought of when I read your original post, cause this is the exact same symptoms.

That original cluster has since been destroyed beyond use, and replaced with one from a newer bike.