[daktah]

so i got a set of gauges from ebay, guy listed they were "used and working in good condition", but when i got them the tach needle has a lot of resistance and sticks at random points and the speedo whines over 10 mph and will wildly flop between my speed and 0. so i left my negative feedback and decided id try to fix them because cosmetically theyre in good shape and dirt cheap. is there a guide for fixing these issues or anyone have any ideas how to fix the whining and flopping and sticking?

 

[brokencamchain]

I don't know how to fix them, but if you want to open them, take small sheet of plywood, 2'x2' x 1/2" and cut a round hole in it so the gauge will slip into it and stop. You want the gauge to slip in, but not go all the way through. The plywood will hold the upside down gauge steady while you gently pry the folded edge over a little bit at a time. You will need a holesaw or something that will leave a nice round hole. (May require sanding the hole so it is smooth) You can use a cheap digital caliper from HF to get the diameter of the needed hole.

Once you get it open and apart you can swap innards from a working gauge that maybe is not as good cosmetically. A rag or towel will shield the clear face of the lens and hold it in place as you work around the back of the gauge. I wish I had pictures, but they are in my head--its been a long time since I did this, but it works. Note: this procedure describes gauges from 68-78 or so and may or may not work on your gauges
You will have to remove the "Cup" from the back to gain access to the crimped area.

 

[joolstacho]

If you can prize the bezel off without damaging it too much... (care), often you can clean a sticky mechanism by flushing it with Meths, (denatured alcohol?).
Then use thin oil VERY sparingly on pivots etc, and refit the bezel. When you take it apart watch out for a little screw that holds the reset knob on, remove that with care (I have a feeling some of these screws might be left handed thread - but don't quote me on that!)

 

[longdistancerider]

How to Open a Honda CB/CX/GL Style Tachometer and Speedometer: 4 Steps
How to Repair a Motorcycle's Speedometer | Gone Outdoors | Your Adventure Awaits

 

[ancientdad]

If only I'd thought of the plywood idea myself back in the day or knew someone who knew it... I struggled with many a tach and speedo back then and recently as well on my 450. PITA Lefty mentioned it a while back too, posted a pic of his... #hindsight2020

 

[dtsmjr8dan]

Here's a pretty good tutorial.

Honda CB Gauge Disassembly and Face Replacement

 

[daktah]

thanks for the disassembly tutorials, but im looking for how to actually repair the internals like joolstacho posted but hoping for specific "if this is happening do this to that"

 

[justlook]

thanks for the disassembly tutorials, but im looking for how to actually repair the internals like joolstacho posted but hoping for specific "if this is happening do this to that"

I'm not sure what you meant by "whining", but my speedo had the bouncing issue. As previous posts and other forums mention, the problem is the damping fluid dried up or leaked out when the gauge was stored face down. I found the damping pot difficult to access because there is a bracket that is tacked to the plate that the face screws into. Rather than Dremel it apart, I was able to carefully lower the needle post assembly while still connected to the spring. It seemed like I could easily damage the spring at that point, but it did work out for me. Adding the fluid to the damping pot solved my needle bouncing issue.

Sorry I don't have photos of the whole process.

 

[longdistancerider]

What is 30,000 cSt differential fluid?

 

[justlook]

What is 30,000 cSt differential fluid?

It is used for RC cars. This is what I used, from tower hobbies. http://www3.towerhobbies.com/cgi-bin/wti0095p?FVSEARCH=LXATJP

 

[longdistancerider]

Thanks for that information, had no idea.

 

[Gixxer-18]

FWIW If you wrap insulation tape around the bezel to protect it and then fit a Jubilee clip so that the outside face is protected and the clip level with the back of the bezel you can then lift up the back of the bezel fairly easily with a small screwdriver working a bit at a time to remove it. Also you can get replacement bezels from CBfaces.com though they're not cheap.
HTH
Nigel.

 

[justlook]

FWIW If you wrap insulation tape around the bezel to protect it and then fit a Jubilee clip so that the outside face is protected and the clip level with the back of the bezel you can then lift up the back of the bezel fairly easily with a small screwdriver working a bit at a time to remove it. Also you can get replacement bezels from CBfaces.com though they're not cheap.
HTH
Nigel.

Had to look up the term "jubilee clip", and after finding out it was a hose clamp, I realized this is the method I used as well. I used a paint can opener to get it started and it worked great. Once it is started I worked around it with pliers pulling it against the hose clamp (hose clamp is tight against the outer side of the silver bezel). To reinstall, I worked around the bezel pushing a screwdriver against the lip that needs to be bent inward. After it was bent a bit, I put the hose clamp set loosely around the black housing (taped for protection), and used the pliers between the edge of the hose clamp and the slightly bent part of the silver bezel ring. That way the pressure on the exposed part of the silver bezel was distributed and it was not marred.

Btw, the cb750faces.com replacement bezel seems slightly thicker than the oem one, and I can not figure a way to crimp it evenly. It comes in an L profile, so there is no pre-existing crease. I recommend trying your best to reuse the existing bezel ring.

 

[Don G.]

I know this is an old thread, but it seems like it has the type of info I'm looking for and now questioning.

I was all set to make my off-season project fixing my spinning faceplate on my tach. But after taking a closer look, I see that my gauges have that rubber vibration thingie between the two halves of the housing (pic attached). All these step-by-step- tutorials seems to be regarding the housing that's just put together with that bezel. I don't see a lip to pry on the housing of mine. Is there another alternative?

 

[longdistancerider]

There's a rubber insert to the gauge backing plate that is a vibration damper, still available from Honda. Typically it's glued itself to the gauge and the back plate so you end up prying between the back and the thin chrome ring on the gauge to get it out. Replace items 9 and 11

 

[Don G.]

Thanks. I'm starting to think it may be less problematic to find a used tach from a salvage place or another owner. Problem is, any I've seen are the other style without the rubber insert.

 

[longdistancerider]

Taking them apart and back together can be a real pain. There's some on eBay. The 2 smaller, 10mm, nuts have to come off the get the chrome cover plate off and then it's just a pull/pry out of the gauge. Shouldn't be hard since that's the only way to replace the bulbs inside.

 

[Don G.]

Happy Thanksgiving, all!

We're having a late dinner for the holiday, so I figured I'd put my time to good use by attempting the tach separation and fix. It took a while, but I got the two halves apart using the paint can opener and pliers method. But imagine my surprise when I did NOT find the missing screws that hold the face plate on and in my case would have keep it from spinning around wildly. I don't know where the heck the screws could have gone, but they're nowhere in the housing, so I guess it means I'll need to replace them. Anyone have any idea what specifications they are? I know they're black, but beyond that I'm at a loss. I don't see them referenced in the fiche. And while I'm at it, I'll ask a couple more questions...because that's what I do. Here goes.

1. As mentioned, what size/type of screws should I get to secure the gauge face?
2. Once I get them and put them on, should I use Loctite (or nail polish or something else) to keep this from happening again? I'm assuming it was a result of normal vibration.
3. I'm generally a 'if it ain't broke, don't fix it' kind of guy, but while I have this thing open, anything else I should do to the internals that would make things better and that I wouldn't likely screw up?

I bought a replacement rubber meter cushion, so that will be replaced when I put it back together. I also bought replacement bulbs, so I'll replace those before I re-install. And I'll clean the glass. I'm guessing Windex or other glass cleaner will be fine for that?

Thanks in advance for your thoughts, and I hope you all have a terrific holiday with friends and loved ones! I know i'm certainly thankful for a lot, not the least of which is having found this forum.

Don

 

[longdistancerider]

On the CL350 speedo the screws were either 2 or 2.5mm, can't remember which but pretty sure 2mm.
Belmetric sells tiny screws, https://www.belmetric.com/2mm-c-10_74_1342_1344_967/ Not sure on length but 6mm or 8mm should do.
A spot of Blue Locktite will secure them.
Windex is fine for the glass

 

[Don G.]

Thanks, Jim. I realized after I posted that I probably should have moved it over to Electrical. Glad you found it, though, and had some answers. I'll check out that link you provided.