Author Topic: Speedometer / Tachometer Rebuild  (Read 1973 times)

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Offline Mark K

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Speedometer / Tachometer Rebuild
« on: July 25, 2022, 05:13:43 AM »
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.
Current bikes
'73 Honda CB750K3 (current project), '19 Kawasaki KLX 140G, '72 Honda CL70K3, '70 Honda SL350 (next project)

Former bikes
'74 Yamaha 60, '72 Maico 250, '74 Kawasaki 250 S1, '82 Kawasaki KZ550, '84 Honda VF700F Interceptor, '99 HD FLSTS Heritage Springer, '97 HD FLHTCUI Ultra Classic '05 HD FLHT Electraglide, '9? Buell Lightning, '03 FLHTCUI Ultra Classic,'14 Honda CRF250L

Offline PeWe

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Re: Speedometer / Tachometer Rebuild
« Reply #1 on: July 25, 2022, 05:38:37 AM »
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.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline newday777

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Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline PeWe

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Re: Speedometer / Tachometer Rebuild
« Reply #3 on: July 25, 2022, 06:44:09 AM »
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.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline MauiK3

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Re: Speedometer / Tachometer Rebuild
« Reply #4 on: July 25, 2022, 07:44:03 AM »
I send my gauges to CB750 Faces, perfect work.
1973 CB 750 K3
10/72 build Z1 Kawasaki

Offline Little_Phil

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Re: Speedometer / Tachometer Rebuild
« Reply #5 on: July 25, 2022, 07:58:20 AM »
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.

Offline Stev-o

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Re: Speedometer / Tachometer Rebuild
« Reply #6 on: July 25, 2022, 11:38:22 AM »
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.
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline Mark K

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Re: Speedometer / Tachometer Rebuild
« Reply #7 on: July 26, 2022, 08:29:10 PM »
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.
Current bikes
'73 Honda CB750K3 (current project), '19 Kawasaki KLX 140G, '72 Honda CL70K3, '70 Honda SL350 (next project)

Former bikes
'74 Yamaha 60, '72 Maico 250, '74 Kawasaki 250 S1, '82 Kawasaki KZ550, '84 Honda VF700F Interceptor, '99 HD FLSTS Heritage Springer, '97 HD FLHTCUI Ultra Classic '05 HD FLHT Electraglide, '9? Buell Lightning, '03 FLHTCUI Ultra Classic,'14 Honda CRF250L

Offline Kevnz

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Re: Speedometer / Tachometer Rebuild
« Reply #8 on: July 26, 2022, 09:43:15 PM »
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.
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Offline Shtonecb500

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Re: Speedometer / Tachometer Rebuild
« Reply #9 on: July 26, 2022, 10:07:52 PM »
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.
73/74'' CB500/550 resto-mod - sold
75' 750f 91' cbr f2 swap cafe - mock up
74' 750 chopper hardtail - complete - sold
74' CB750/836kit - Black mix & match - daily rider - always tweaking
71' cb500 K0 survivor - complete
71' K1 - CANDY GOLD/BROWN Winton kit - in process

Offline Mark K

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Re: Speedometer / Tachometer Rebuild
« Reply #10 on: July 27, 2022, 12:24:54 PM »
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?
Current bikes
'73 Honda CB750K3 (current project), '19 Kawasaki KLX 140G, '72 Honda CL70K3, '70 Honda SL350 (next project)

Former bikes
'74 Yamaha 60, '72 Maico 250, '74 Kawasaki 250 S1, '82 Kawasaki KZ550, '84 Honda VF700F Interceptor, '99 HD FLSTS Heritage Springer, '97 HD FLHTCUI Ultra Classic '05 HD FLHT Electraglide, '9? Buell Lightning, '03 FLHTCUI Ultra Classic,'14 Honda CRF250L

Offline Mark K

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Re: Speedometer / Tachometer Rebuild
« Reply #11 on: July 27, 2022, 12:28:28 PM »
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.
Current bikes
'73 Honda CB750K3 (current project), '19 Kawasaki KLX 140G, '72 Honda CL70K3, '70 Honda SL350 (next project)

Former bikes
'74 Yamaha 60, '72 Maico 250, '74 Kawasaki 250 S1, '82 Kawasaki KZ550, '84 Honda VF700F Interceptor, '99 HD FLSTS Heritage Springer, '97 HD FLHTCUI Ultra Classic '05 HD FLHT Electraglide, '9? Buell Lightning, '03 FLHTCUI Ultra Classic,'14 Honda CRF250L

Offline Don R

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Re: Speedometer / Tachometer Rebuild
« Reply #12 on: July 27, 2022, 12:42:06 PM »
 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.
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Offline grcamna2

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Re: Speedometer / Tachometer Rebuild
« Reply #13 on: July 27, 2022, 01:13:48 PM »
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..
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline MauiK3

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Re: Speedometer / Tachometer Rebuild
« Reply #14 on: July 27, 2022, 02:52:00 PM »
CB750 faces can be slow but the work is great.
1973 CB 750 K3
10/72 build Z1 Kawasaki

Offline Kevnz

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Re: Speedometer / Tachometer Rebuild
« Reply #15 on: July 27, 2022, 03:27:44 PM »
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.
Good grammar: The difference between knowing your #$%* and knowing you're #$%*

Offline newday777

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Re: Speedometer / Tachometer Rebuild
« Reply #16 on: July 28, 2022, 03:23:37 AM »
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?
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline grcamna2

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Re: Speedometer / Tachometer Rebuild
« Reply #17 on: July 28, 2022, 09:14:37 AM »
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.
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline newday777

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Re: Speedometer / Tachometer Rebuild
« Reply #18 on: July 28, 2022, 10:06:06 AM »
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 😊
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline jlh3rd

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Re: Speedometer / Tachometer Rebuild
« Reply #19 on: July 28, 2022, 10:52:09 AM »
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.

Offline PeWe

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Re: Speedometer / Tachometer Rebuild
« Reply #20 on: July 28, 2022, 12:00:14 PM »
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 ;D
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.
« Last Edit: July 28, 2022, 08:46:58 PM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Mark K

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Re: Speedometer / Tachometer Rebuild
« Reply #21 on: July 28, 2022, 08:53:21 PM »
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
Current bikes
'73 Honda CB750K3 (current project), '19 Kawasaki KLX 140G, '72 Honda CL70K3, '70 Honda SL350 (next project)

Former bikes
'74 Yamaha 60, '72 Maico 250, '74 Kawasaki 250 S1, '82 Kawasaki KZ550, '84 Honda VF700F Interceptor, '99 HD FLSTS Heritage Springer, '97 HD FLHTCUI Ultra Classic '05 HD FLHT Electraglide, '9? Buell Lightning, '03 FLHTCUI Ultra Classic,'14 Honda CRF250L

Offline PeWe

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Re: Speedometer / Tachometer Rebuild
« Reply #22 on: July 28, 2022, 11:04:23 PM »
L shaped ring.
Ready to be closed on its not visible side.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Mark K

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Re: Speedometer / Tachometer Rebuild
« Reply #23 on: July 29, 2022, 11:59:54 AM »
Thanks PeWe
Current bikes
'73 Honda CB750K3 (current project), '19 Kawasaki KLX 140G, '72 Honda CL70K3, '70 Honda SL350 (next project)

Former bikes
'74 Yamaha 60, '72 Maico 250, '74 Kawasaki 250 S1, '82 Kawasaki KZ550, '84 Honda VF700F Interceptor, '99 HD FLSTS Heritage Springer, '97 HD FLHTCUI Ultra Classic '05 HD FLHT Electraglide, '9? Buell Lightning, '03 FLHTCUI Ultra Classic,'14 Honda CRF250L

Offline Mark K

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Re: Speedometer / Tachometer Rebuild
« Reply #24 on: August 01, 2022, 03:58:58 PM »
Painted the back sides of the new guage faces. Paint color match almost perfect.
Current bikes
'73 Honda CB750K3 (current project), '19 Kawasaki KLX 140G, '72 Honda CL70K3, '70 Honda SL350 (next project)

Former bikes
'74 Yamaha 60, '72 Maico 250, '74 Kawasaki 250 S1, '82 Kawasaki KZ550, '84 Honda VF700F Interceptor, '99 HD FLSTS Heritage Springer, '97 HD FLHTCUI Ultra Classic '05 HD FLHT Electraglide, '9? Buell Lightning, '03 FLHTCUI Ultra Classic,'14 Honda CRF250L