Topic: Speedometer Repair

[jmelche2]

Has anyone had success repairing a speedometer?  I have a '74 CB550 and the speedo gets stuck around 20 or so.  I know it is not the cable because that is turning fine.  I would prefer to fix this one rather than sourcing another from Ebay.  Is this the correct speedo for '74 CB550?

[newday777]

Yes it looks like one for a 74

[jlh3rd]

Honda's book doesn't give a face color for the '74 K0 speedometer. It does say '75 K1's were dark green and '76 was light green. Then not mentioned for the '77 K model.
However, the '77 F model were dark blue.
So, no direct proof. The age cracks fit, and you're sure it's a '74 K0. No one can prove your color isn't correct.

[Rayzerman]

DIY?

https://www.dimecitycycles.com/blog/honda-cb-gauge-disassembly-and-face-replacement.html

https://www.cb750faces.com/en/25-honda-cb350-four-and-twin

[fire113]

Has anyone had success repairing a speedometer?  I have a '74 CB550 and the speedo gets stuck around 20 or so.  I know it is not the cable because that is turning fine.  I would prefer to fix this one rather than sourcing another from Ebay.  Is this the correct speedo for '74 CB550?

Yes, its looking like CB550 K0 74 but keep in mind that You buy the face plates with nippon seiki brand and not nippon denso!, both available. You can find the needed parts here-> https://www.cb750faces.com/en/28-honda-cb550-four

But that won't fix You problem, if Yor speedo gets stuck around 20 then You have dirt inside that is blocking the mechanic or You or the PO have stroed the gauge wrong and the leaked oil gummed up the mechanic that it will stick if You reach 20.
You need to disassemble the mechanic to be able to clean the moving parts from the sicky oil.
If it will be dirt, then You can try compressed air to get the drit away.
If I am back at the office I can send You some pictures then You can see it.

Have a good one...Georg

[jlh3rd]

so, to the OP: since you're being presented with these options.
just a FYI if you're unfamiliar with dealing with these gauges. It can be a rabbit hole. The biggest issue is removing/re/installing the stainless steel crimp ring that holds the gauges together. If you've never done it, it can be.....frustrating. I've done it once, and needed my home made jig to make it ok. Then, if you replace the faceplate on one, you will,probably wanna do the other one.
And the aftermarket faceplates are made of white plastic, with the green coating, and honda's are green plastic. This creates a "whiteout" effect at night with the aftermarket. Some solve the issue by changing bulbs. I used a 3m, stick on, translucent green film on the back of the faceplate. Maybe it's been "fixed", dunno.
And it depends on what matters to you.

[jmelche2]

Found the issue - There was a gel between this surface (see photo) and a cover that goes over it.  The gel was causing a drag between the two and not allowing the needle to move freely.  I cleaned the gel of both surfaces and now the speedometer registers correctly.  However, I do notice and slight needle bounce at higher speeds.  I am now thinking the gel was probably there to act  as a damper but should only be on one surface, not both.  You can see the gel in the second photo.

[fire113]

...the gel is the daper oil, it left the reservoir and spread over the part(s), so it was dored wrong.
The reservoir is behind the counter roll but take care if You going to disassemble the machanic to be able to fill up the damper oil...if You bent the spring...not good, won't work correct any longer.

Edit-> You can get standard and special version of the after market face plates but You have to ask.
Here You can see the special version of the face plates:


Have a good one...Georg

[denward17]

...the gel is the daper oil, it left the reservoir and spread over the part(s), so it was dored wrong.
The reservoir is behind the counter roll but take care if You going to disassemble the machanic to be able to fill up the damper oil...if You bent the spring...not good, won't work correct any longer.

Edit-> You can get standard and special version of the after market face plates but You have to ask.
Here You can see the special version of the face plates:


Have a good one...Georg

Georg,
How was it stored wrong?  Upside down?

[fire113]

...yes, upside down or on the side of the cover, store the gauges always near like mounting position...sunny side up.

Have s good one...Georg

[beemerbum]

The tach on my 1971K1 750 has a warped face plate. The needle gets stopped at 4000 rpm. In all other respects as to appearance, it is in like new condition. The disassembly of the instrument is something I would never attempt myself. Can the faceplate somehow be flattened without disassembly, although that sounds impossible? Is there anyone in the US who does that type of instrument repair?

[fire113]

...no, You have to open the gauge and change the face plate but if You only change one face plate You will see a color difference so You have to do both gauges.

Don't know who is doing gauge service in the us.
In Germany is a good gauge repair shop called Tachowerk, good work-> https://tachowerk.de/fotos

Best Regards Georg

[beemerbum]

...no, You have to open the gauge and change the face plate but if You only change one face plate You will see a color difference so You have to do both gauges.

Don't know who is doing gauge service in the us.
In Germany is a good gauge repair shop called Tachowerk, good work-> https://tachowerk.de/fotos

Best Regards Georg

Danke!