Topic: How to refill speedo damper pot?

[Honda-Rog]

I've read many of the posts on here about this, but nowhere can I find how to actually get to the pot (My clocks are the larger face ones on the CB550). I've removed the crimp ring, needle and faceplate, so have got as far as the actual mechanics inside.

Is there a way of removing the trip mileage unit, which I think would help me get to the damper, and then drill and inject; or is there a way of removing the top plate? Or some other means?

I really don't want to foul up my speedo, but it swings all over the place when I accelerate or decelerate, then eventually settles down. Above 50 I can't be sure of my speed.

BTW I am in awe of the Honda techs who designed and built such a device! Provided of course that I can get it working as it should 

All advice most welcome.

Rog, in the UK

[Muckinfuss]

Sometimes, and I stress sometimes, the issue with needle swings is the speedo cable binding.  Make certain that it's in top shape first...no worn liner.  Next, hook up an electric drill to the cable end, using a new cable, while the speedo is also connected and spin it.  If the needle is jumping, then you have a speedo issue.  If not, you have a cable, or speedo drive issue.  If it's the speedo, then clean all exposed parts with alcohol or better yet, Mass Air Flow Cleaner (areosol can) from an auto parts store.  When clean, a little white grease on the moving parts.  Try the drill/cable thing again.  There are SOHC gauges with a 'door' on the damper cell that can be removed and filled with a very thin silicone based oil like that used in Radio Control Car differentials.

Here is a write up for the complete process:   http://www.oldjapanesebikes.com/GT750J_Gauge/page-3

[Don R]

Don't spin it backwards

[dave500]

they wernt made by Honda.

[Kenzo1979]

You can also use the appropriate sized square bit in the power driver/drill to check your gauges without the cable.

[DH]

Sometimes, and I stress sometimes, the issue with needle swings is the speedo cable binding.  Make certain that it's in top shape first...no worn liner.  Next, hook up an electric drill to the cable end, using a new cable, while the speedo is also connected and spin it.  If the needle is jumping, then you have a speedo issue.  If not, you have a cable, or speedo drive issue.  If it's the speedo, then clean all exposed parts with alcohol or better yet, Mass Air Flow Cleaner (areosol can) from an auto parts store.  When clean, a little white grease on the moving parts.  Try the drill/cable thing again.  There are SOHC gauges with a 'door' on the damper cell that can be removed and filled with a very thin silicone based oil like that used in Radio Control Car differentials.

Here is a write up for the complete process:   http://www.oldjapanesebikes.com/GT750J_Gauge/page-3

Anyone know how/where to add the oil into the pot? I have a 750 speedo in pieces that looks similar to the suzi gauge featured in the link, and the "frame" around the inner components is notched and stamped closed, not
made to be dis assembled, so you cant see the top of the pot.

[Honda-Rog]

Yeah, that's my problem too! I'm sure the cable is fine, already checked; the gauge swings freely, but if I operate if manually, the needle shoots right back to 0, so there's no damping at all.

Anyone taken one of these right back to components?

[grcamna2]

This is a great thread 

[fire113]

http://forums.sohc4.net/index.php?topic=117107.0

Have a good one mate...Georg

[Honda-Rog]

Georg,

Thanks for that link, but my speedo is different inside to that - no circlips, for one.

BUT - I've done it! I took my dremel and carefully cut away the metal tags which were retaining the odometer unit, until I could prise it away. That left the pot visible, so I drilled into it, and added some oil - in the end a mixture of sewing machine oil and a somewhat heavier one  .

At that stage the needle would still rocket back to 0, but I reassembled nevertheless, using epoxy putty to hold the odometer in place. If you try this, be careful not to epoxy the odometer to the frame, or your mileage will stay the same for ever!

For interest's sake, not to spark another discussion, I will tell you how I also adjusted the odometer reading to match that on my old speedo, which was the original one for the bike (allowing a little for the extra mileage since I swopped them over). I found I could move the individual wheels around whilst holding the 'dividers' in place. So one job done, at least.

With the speedo back on the bike, the needle is much more steady, not 100% perfect, but much more acceptable, with just a slight tremor. So I'm reasonably content with this. The only issue I had was that I hadn't put the needle back on in the correct place, with the result that the speedo was reading 10-15 mph over. Fortunately I'd cut the retaining ring, so it was fairly easy to get back inside and reposition - may have to do this a couple of times with road testing before it's right.

But, it was nerve racking, especially the dremelling part!

Thanks for the input guys. Sorry it's such a wordy post.

[DH]

 

Georg,

Thanks for that link, but my speedo is different inside to that - no circlips, for one.

BUT - I've done it! I took my dremel and carefully cut away the metal tags which were retaining the odometer unit, until I could prise it away. That left the pot visible, so I drilled into it, and added some oil - in the end a mixture of sewing machine oil and a somewhat heavier one  .

At that stage the needle would still rocket back to 0, but I reassembled nevertheless, using epoxy putty to hold the odometer in place. If you try this, be careful not to epoxy the odometer to the frame, or your mileage will stay the same for ever!

For interest's sake, not to spark another discussion, I will tell you how I also adjusted the odometer reading to match that on my old speedo, which was the original one for the bike (allowing a little for the extra mileage since I swopped them over). I found I could move the individual wheels around whilst holding the 'dividers' in place. So one job done, at least.

With the speedo back on the bike, the needle is much more steady, not 100% perfect, but much more acceptable, with just a slight tremor. So I'm reasonably content with this. The only issue I had was that I hadn't put the needle back on in the correct place, with the result that the speedo was reading 10-15 mph over. Fortunately I'd cut the retaining ring, so it was fairly easy to get back inside and reposition - may have to do this a couple of times with road testing before it's right.

But, it was nerve racking, especially the dremelling part!

Thanks for the input guys. Sorry it's such a wordy post.

Where did you drill into it at? What kind of drill did you use, and what size bit?
Please share with us

[fire113]

...don't drill any holes!
Just lift that little cap on the top of the pot and fill in a little bit silicon oil BUT DON'T OVERFILL IT!!!

[Honda-Rog]

Too late, Fire113. I used a 1.5mm bit (smallest I own) in a Dremel, took about three seconds to go through.

Presumably if you overfill it dribbles out of the hole - any other dire consequences I should have thought of? Everything seems OK now.

[fire113]

Too late, Fire113. I used a 1.5mm bit (smallest I own) in a Dremel, took about three seconds to go through.

Presumably if you overfill it dribbles out of the hole - any other dire consequences I should have thought of? Everything seems OK now.

...if You fill in someting else the silicon oil, I am sure it won't work!
And if there is any hole in the pot it will leak out the hole and glue everyting with silicon oil, the speedo spring too!!! and that will bring up wrong reading for speed or RPM!

I wish You good luck...Georg

[DH]

Man, that stinks ........There was a thread here some time ago that covered this very operation and I'd swear it said that it was necessary to drill certain types
of instruments, that the "lid" was not removable. sorry to hear that.

[fire113]

Man, that stinks ........There was a thread here some time ago that covered this very operation and I'd swear it said that it was necessary to drill certain types
of instruments, that the "lid" was not removable. sorry to hear that.

...I never drilled holes into the pot to refill it and I did all kind of cb750 gauges (K0 to K6 / F2).
Just remove the glue and lift the little cap on the top of the pot to be able to refill it.

EDIT--> Here You have some pictures from the last gauges that I did.

[grcamna2]

Nice pics and nice work fire113,a couple questions:what type of glue do you use to seal it back up so it won't leak ? and what type of welder or solder did you use to re-install the steel frame ?

[fire113]

...I use Pattex or You can steal the finger nail stuff from You wife 
I soldered it with an butane gas driven soldering iron, is making a lot of heat that You will need
to heat up the parts but be careful !!! One wrong move and the gauge is toast !

Have a good one...Georg

[grcamna2]

Again Nice work Georg  Have you ever done CB350/400F speedo or tach.,the smaller ones ? I wonder if they have the same type of damper pot w/ removable cap ?

[Honda-Rog]

Should have said I sealed the hole with epoxy putty - very useful stuff, epoxy putty  To my shame I took absolutely no notice of previous posts on the viscosity of the oil. I guess we'll see how it all pans out.

Fire113, out of interest, how did you remove the top plate to access the pot cover?

This is fun!

[fire113]

...nope! never did a CB350/400F speedo or tach but it should be a kind of same mechanic inside.
To remove the top plate (<-I call it this way ) I used a Dremel and sanded down the little pins.