Topic: Speedometer / Tachometer Rebuild

[Mark K]

In the process of rebuilding the speedometer and tachometer for a 750K3. Pried open the ring on the speedo to get the halves separated. Read someone's post about cutting the ring for easier removal. My question is how to get the two halves to stay together when the ring no longer has any tension to hold them together, since the rings are now cut? Is there an alternative way to join the two halves?

Mark K.

[PeWe]

It is very common that people open the ring without cutting it.
A sharp screwdriver or paint can opener. Bend it open in small steps going around until parts can be separated.

The reversed method when assembly.
Open the side facing downwards.

[newday777]

You can order new rings.

https://www.vintagecb750.com/products/117/tach-speedo/120/mounts-rubbers-hardware

https://www.cb750faces.com/en/18-honda-cb750-k3-1973

[PeWe]

I have new rings from cb750faces, they are really hard. A good tool with a good plan needed. I paused my CB750 K2 speedo and tacho restorations.
Bought NOS gauges I was lucky to find for not horrible prices as seen nowadays.

[MauiK3]

I send my gauges to CB750 Faces, perfect work.

[Little_Phil]

My question is how to get the two halves to stay together when the ring no longer has any tension to hold them together, since the rings are now cut? Is there an alternative way to join the two halves?

Mark K.

I've done them both ways. When I cut the ring, I refitted it with glue and a large jubilee clip to hold tightly it in place until cured. Make sure you get the join in the least easiest seen place. But prising the band is generally better as often when finished it is not noticeable at all as it sits in its cushioning.

[Stev-o]

I send my gauges to CB750 Faces, perfect work.

I know of a guy in Europe that sent his gauges there in Jan and still has not received them back.

[Mark K]

Thanks for all the responses. I did pry open the speedo ring. Was having fits trying to get the ring back on and read somewhere on the forum that someone had cut theirs. Cut the tach ring and am now where I am. Not sure how one would install a new ring, as it'd have to be pried open somehow. Was going to buy aftermarket speedo & tach, but saw many of those don't seem to last too long. Figured rebuilding would be the better bet...

Have found chrome covers that have a clamp, https://www.vintagecb750.com/products/117/tach-speedo/120/mounts-rubbers-hardware

Sent an inquiry to find out if the clamp is solidly attached to cover, or is it able to be removed. I'd be fine with using a clamp.

[Kevnz]

I got rings and faces from 750facescom. Made this tool to fit, based on a post by a member here, just fit the guage in and press slowly and gently to flatten the ring. TEST GUAGES before flattening completely; I hadn't fitted the needle properly and it slipped.

[Shtonecb500]

Thanks for all the responses. I did pry open the speedo ring. Was having fits trying to get the ring back on and read somewhere on the forum that someone had cut theirs. Cut the tach ring and am now where I am. Not sure how one would install a new ring, as it'd have to be pried open somehow. Was going to buy aftermarket speedo & tach, but saw many of those don't seem to last too long. Figured rebuilding would be the better bet...

Have found chrome covers that have a clamp, https://www.vintagecb750.com/products/117/tach-speedo/120/mounts-rubbers-hardware

Sent an inquiry to find out if the clamp is solidly attached to cover, or is it able to be removed. I'd be fine with using a clamp.

I was outgoing to recommend these as well, they are incredibly tight fitting and great alternative to cleaning up stock units.

[Mark K]

I got rings and faces from 750facescom. Made this tool to fit, based on a post by a member here, just fit the guage in and press slowly and gently to flatten the ring. TEST GUAGES before flattening completely; I hadn't fitted the needle properly and it slipped.

Kevnz,

Is the ring in the picture the ring you received or is it part of the jig you made?

[Mark K]

Thanks for all the responses. I did pry open the speedo ring. Was having fits trying to get the ring back on and read somewhere on the forum that someone had cut theirs. Cut the tach ring and am now where I am. Not sure how one would install a new ring, as it'd have to be pried open somehow. Was going to buy aftermarket speedo & tach, but saw many of those don't seem to last too long. Figured rebuilding would be the better bet...

Have found chrome covers that have a clamp, https://www.vintagecb750.com/products/117/tach-speedo/120/mounts-rubbers-hardware

Sent an inquiry to find out if the clamp is solidly attached to cover, or is it able to be removed. I'd be fine with using a clamp.

I was outgoing to recommend these as well, they are incredibly tight fitting and great alternative to cleaning up stock units.

The company out of Canada, Vintage CB750, said the clamp is part of the chrome cover and does not separate.

[Don R]

 On the old chrome covers, the clamp was separate. I used a set with the covers on to hold my K1 gauges together until I was able to find gauges and parts to make a K0 set. 
 I have used a small straight screwdriver with one side rounded off to keep from leaving crimp marks in the ring. I also made an oak block drilled to hold the gauge front housing while working on them.

[grcamna2]

I found an old school gallon paint can opener and sharpened it a little:works great to remove the original ring.
I used a large drift punch to roll the edges of the original ring back down;that process can be improved on..

[MauiK3]

CB750 faces can be slow but the work is great.

[Kevnz]

I purchased a pair of faces and rings for both instruments. In the past, I have managed to prise the rings open without damage and reuse them, but this speedo had been damaged. If you open them from the back, the repair won't be seen as it sits on the rubber cushion. When assembling, just place the instrument into the jig and gently work your way around flattening the ring with a wide flat blade screwdriver or similar. Finish off with a pair of widebill pliers if necessary. Tacho hasn't been done yet; these are 500\4. As I said before, just crimp it enough to hold together and test it before closing it up completely. If you have trouble removing the needle, there's Youtube footage on how to do it. Otherwise all pretty straightforward.

[newday777]

I found an old school gallon paint can opener and sharpened it a little
:works great to remove the original ring.

Can you take a profile picture of the sharpening you did to the paint can opener?

[grcamna2]

I found an old school gallon paint can opener and sharpened it a little
:works great to remove the original ring.

Can you take a profile picture of the sharpening you did to the paint can opener?

I have it in my tools which are in storage now.

The end of the tool is where I ground(actually filed it)it so it would renew the sharp edge while keeping the inner 'hook' with the same 'curve' to it;those things have a nice edge on them to pick at the factory speedo/tach ring.
The ones sold now(China  )don't have the same hardness to the steel as the vintage Sherwin Williams tool does.

[newday777]

I found an old school gallon paint can opener and sharpened it a little
:works great to remove the original ring.

Can you take a profile picture of the sharpening you did to the paint can opener?

I have it in my tools which are in storage now.

The end of the tool is where I ground(actually filed it)it so it would renew the sharp edge while keeping the inner 'hook' with the same 'curve' to it;those things have a nice edge on them to pick at the factory speedo/tach ring.
The ones sold now(China  )don't have the same hardness to the steel as the vintage Sherwin Williams tool does.

Ok thanks 😊

[jlh3rd]

In the process of rebuilding the speedometer and tachometer for a 750K3. Pried open the ring on the speedo to get the halves separated. Read someone's post about cutting the ring for easier removal. My question is how to get the two halves to stay together when the ring no longer has any tension to hold them together, since the rings are now cut? Is there an alternative way to join the two halves?

Mark K.

If you are replacing the faces, be aware that at night the backlighting is more intense and brighter than the stock faces. That is because the original honda faceplate is green plastic whereas the aftermarket one is white.
Shown here,.... as I re-did a tach that is with this stock new speedo set....The green stick on, translucent sheet you see required two circular cutouts placed on the backside of the white aftermarket to match the backlighting as best as I could tell....fyi.

[PeWe]

I painted my new  K2 faces Found a similar blue-green metallic rattle can.
I do not like the see thru face which stock did not have.

I bought a restored tacho to my K6 that had blinding light when driving in the dark.
I found a low wattage bulb that helped.
I have a complete NOS set to that bike. Too good to be used, still in stock boxes
Bike has its stock speedo showing all km done, now on the 2nd lap.

I have not restored the K2 gauges yet. I have another K2 frame that can use them.

Photo after painted the rear and removed them from the protective paper. Look close to stock color.

[Mark K]

Thanks for tip about the back of the new gauge faces. Mine are white, so I'll have to remove the needle, take face plates off and paint the backsides.

Does anyone know if new crimp rings are already crimped? Or is only one side crimped?

I forgot to order the new rubber seals for the guage glass, figured I might order new crimp rings, if they're not crimped on both sides.

Thanks,
Mark K

[PeWe]

L shaped ring.
Ready to be closed on its not visible side.

[Mark K]

Thanks PeWe

[Mark K]

Painted the back sides of the new guage faces. Paint color match almost perfect.

[PeWe]

Interesting to see how it will look like on the bike when lit.
Stock illumination is very cool.

I have a broken stock K2 faces I could compare the backside color. And the color where broken off.

[Mark K]

Found some clamp rings on Joker Machine (https://jokermachine.com/collections/honda-cb750-parts). Only problem was they had been discontinued. I lucked out, guy there found a set of black rings and sold them to me. Installed the rings, checked to make sure the new bulbs lit and the needles spin using a drill. Installed the gauges on the bike, I like the way they look.