Opening up a speedo/tach

[RustiePyles]

Out for a ride the other day and the screws fell out of the face of my speedo . So I had to open it up to put the screws back in. I know there are other threads where others have done the same but I thought I’d document what I did.

 

[RustiePyles]

I started by removing the speedo, once out I struck a mark on the housing with a sharpie to aid in reassembly.

I cut the housing all the way around with a Dremel cutoff wheel.

After removing the two screws from the back of the housing I gently worked the clockwork out of the housing.

After separating all the pieces I cleaned up the housing with a deburring tool.

 

[RustiePyles]

Using a set of soft jaws I clamped the clockwork in my vise.

Using loctite 220 (wicking) I reinstalled the face screws.

With the face screws back in place I cleaned all the sawdust and gunk off the clockwork with a soft brush and computer duster. Then I lightly lubed all the gears with some light weight grease (SylGlide) and reinstalled the clockwork back into the rear half of the housing.

once assembled, I used a few cut-off wheels in the kerf to re-established the housing depth.

 

[RustiePyles]

With cut-off wheels in place I used rubber bands and four pieces of 3/32 TIG filler rod cut to length to stabilize the housing for glue up.

Applied 5min epoxy in four spots between cribbing and spacers.

Let epoxy cure for about an hour and removed all the bracing and rubber bands. Applied epoxy all the way around.

 

[RustiePyles]

Once my new insulators arrive from partzilla I’ll reinstall the speedo.

 

[jetmechmarty]

Nicely done!

 

[WideAWAKE]

Is there a reason you didn’t just pop the outter ring off??

I mean, it doesn’t get you into the back of the speedo, but if the screw on the faceplate were all you needed to get to...

 

[Mailman]

Very slick work! I like it!

 

[RustiePyles]

Is there a reason you didn’t just pop the outter ring off??

I mean, it doesn’t get you into the back of the speedo, but if the screw on the faceplate were all you needed to get to...

Didn’t want to deform the ring. I’ve done it in the past like that and I’ve never been able to get the bezels perfect again after prying them up.

 

[DogBunny]

Removing the bezel, the usual procedure, is difficult, and it usually looks bad when put back on. I like your solution a lot. Nice details using the cut-off wheels as temporary spacers, and stabilizing everything with the TIG rods and rubber bands.
Next time, to improve adhesion, I'd rough up the plastic where the epoxy gets applied.

Also, I'm not crazy about most epoxies, especially the 5-minute ones. This is what I use. And, I'd add one layer of glass cloth. At certain speeds/rpms/resonances, those gauges vibrate like crazy. That's why your screws backed out.
Nice job! I like it.

 

[RustiePyles]

Removing the bezel, the usual procedure, is difficult, and it usually looks bad when put back on. I like your solution a lot. Nice details using the cut-off wheels as temporary spacers, and stabilizing everything with the TIG rods and rubber bands.
Next time, to improve adhesion, I'd rough up the plastic where the epoxy gets applied.

View attachment 192043
Also, I'm not crazy about most epoxies, especially the 5-minute ones. This is what I use. And, I'd add one layer of glass cloth. At certain speeds/rpms/resonances, those gauges vibrate like crazy. That's why your screws backed out.
Nice job! I like it.

Yeah, I did consider glass-mating it but didn’t have any fiber and my resin was pretty old. I also considered using heavy PVC adhesive, I’m pretty sure the buckets are PVC. But my PVC primer was all dried up. I kinda thought the kerf itself was rough enough for decent adhesion so I didn’t rough up the outside of the buckets any, that may have been a mistake. Only time will tell. FWIW I did order new insulators from part(not available)zilla so that should help a little with vibration moving forward.

 

[WideAWAKE]

Didn’t want to deform the ring. I’ve done it in the past like that and I’ve never been able to get the bezels perfect again after prying them up.

yeah, I’ve found that slow and steady wins the race. And using the smallest pry tool as possible. I usually go around the bezel 3-4 times lightly prying a little more each time until I can get it out. Then do the same putting it back down, lightly tap it down with a flat bar and hammer, then tap the outside with a rubber mallet. Just did it last week and thought about taking photos but lost track of time. I’ll snap some on my next one.

Cutting it open seems like an easy way to get it completely open though.

Epoxy over a pvc really needs a primer to get a good bond. You may not run into any issues with peeling but it could be a possibility (adding fiberglass to the mix won’t do anything to help a bonding issue either). They do rattle around quite a bit but with some good rubber you’ll probably be ok. I’d bet you’ll find out within the first few rides.

edit: I found this pic - just barely open enough to sneak it out.

 

[DogBunny]

Good thoughts. Yes, I think testing a small spot with PVC cement to see if it melts the plastic would be the thing to do. Then, use primer and thick PVC cement.

 

[Jim]

Curious.... anyone know if they make a pipe cutter big enough to fit these gauges?

 

[Rhy650]

Great idea, I have ruined a tach trying to get the bezel off, this is a much better approach.

 

[WideAWAKE]

Curious.... anyone know if they make a pipe cutter big enough to fit these gauges?

I see plumbers using them on 4-6” pipe all the time.

 

[5twins]

I think this is a pretty radical approach, cutting the thing in half like that, lol. I've been into a few of these and always just pried the ring off. With the proper tools and technique, they've always come out fine.

 

[650Skull]

Good pics. and well thought out.

Notice the crack around the mounting bolt. They always cracked there, the housing always looks as though the plastic has had heat applied as well, (the discolouring), this is caused by heat from the vibration. My concern is that epoxy being brittle, coupled with the vibration, it will crack it. When removing the bezels with the screwdriver method using the case a leverage point I was surprised at how much flex was in the plastic housing..........Not trying to put a hex on it

I'll add this to keep relevant information together
http://www.xs650.com/threads/70-83-...damper-replacement-replace-face-decals.52013/

 

[Jan_P]

Curious.... anyone know if they make a pipe cutter big enough to fit these gauges?

Good idea ..and such pipe cutters exists ..But those I have seen are a bit Heavy handed things
Up to 6 " at least for steel pipes
Heavy and exerting large forces ..risking to crack the plastic

 

[Jan_P]

On # 5 second last picture
Stud 12 o clock it looks as a crack in the plastic.
I would give it is some epoxy around it to try prevent further crack propagation.
Nice work !