speedometer disassembly idea/question

[beechfront]

i have read on here about cutting around the speedometer for disassembly. well i had a thought tonight.

what about instead of cutting all the way around - just cutting a decent sized hole in the plastic? seems to me if you could set your dremel bit to a very shallow depth, it would be easy to cut a hole large enough to clean the gears without damaging the insides. then just wrap duct tape around the plastic housing a couple times to cover the hole back up. would also be easy to get apart again if needed. would look perfectly stock once put back together too.

those that have disassembled a speedometer already - do you think that this would work? and if so - could you advise me on the best location for this hole?


THANKS!

[ratbyk]

Speedo Repair

Hey, Beechfront, good thought, good question. I hope you get some usable responses. That is a great idea. Heck of a lot easier than taking a chance of disassembling the whole thing. Particularly if all you plan to do is flush it out and then lubricate.
Should be do able. I have had a few speedos apart over the years, but never an XS's. Almost always ended up breaking off some critical part. Lots of bits laying around from failures.
I like your thinking.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"
92 ZX11 Temptress

[Dennyz]

Hi Beachfront!

I am not sure where you are considering boring the hole. The gauges are housed in metal, not plastic.

I have been very successful at opening gauge unit with a flat blade screw driver to pry the crimped edge of the bezel away from the gauge housing. I found if I pry up 3 of the 4 sides, I can slip the bezel off. Then I clean up the crimp area with a strong pair of square end pliers. I use a flat tip punch to re-crimp the bezel back on to the housing.

[beechfront]

if you remove the two screws in back - the metal housing comes off. this is how you replace the light bulbs. the rubber 'seal' towards the front of the guage makes it a little tricky, but not impossible. i've had two different guages apart this way.


not sure maybe my 79 special is different than your F

[scoobes]

i went the easy way and bought nos rev counter and speedo cost me £90 nice and shiny with no miles on.

[Dennyz]

Beachfront,

I have taken apart several Standard (square) and Special (round) gauges both speedos and tachs, '78 thru '80. All had metal housed instruments inside the black (Standard) or chrome (Special) metal instrument cluster shell.

The attached image is a Special tach (SF) and a Standard (G) speedo. Both have metal housings. I have a 1/2 dozen of these in various forms of brokeness. All have metal cases.



The question I have is: What type of gauges do you have that have plastic cases?

[beechfront]

hmmm. that's strange.


i am 90% certain mine are both plastic. white plastic.


both are 160mph speedos from 79sf



i will hopefully verify tonight.

[Dennyz]

I stand corrected! I just opened a '80 speedo and it does have a plastic case. I guess I never opened up a Special speedo. It has always been the tachs that needed opening.

Jumping speedos has always been the cable, for me.

[beechfront]

mine is not jumping.


it's just VERY slow to react.



if you or anyone could recommend a place to cut a hole i'd be willing to try it.

[Ken Talbot]

Originally posted by beechfront
mine is not jumping.
it's just VERY slow to react.

Maybe you just need to twist your wrist a bit more

[ratbyk]

Speedo Repair

Most of my successful speedo repairs have been with the odometer portion not the speedo portion. All successful repairs were done with minimal disassembly.
When disassembling the "main" frame inside it is usually held together with little bent over tabs on the corners that hold it together. Most of the time I was able to "unbend" the tabs to get it apart but on re-bending while trying to reassemble the tabs would break off. Sh__t!
Successful repairs usually were accomplished by flushing out the interior/cogs/wheels etc. with alcohol and then lubricating with sewing machine oil that would nick off my wife.
The speedo portion consists of a magnetic drum shaped piece spun by the speedo cable. Sitting in the center of this spinning magnetic field is a flat disc which turns the "axle" to the needle. The faster the magnetic field is spun the more the "axle" and needle are rotated. There is a very small coiled "hair" watch type spring at the base of the needle which slows it's advance and returns it to zero.
Go slow, wear magnifying glasses and don't disassemble any farther than absolutely necessary.
Lots of luck.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat
92 ZX11 Temptress

[beechfront]

well the odometer seems to work just fine. what do you think could be causing my speedo issues then? maybe it isn't worth tearing into it. i would hate to ruin something. might be better if i just go buy another $35 digital speedo.

[desert1]

gas gauge

Never had a gas gauge that worked. My 78 has the swing gauge and I believe the problem to be in the swing gauge itself. Bought another tach on ebay and darn that gauge never worked either. Glad my tripometer works!
Bruce
78 XS1100 Alpha
79 Special

[ratbyk]

Slow Speedo

Is it possible that the speedo cable has been over lubricated? I have encountered that in the past. The turn (screw effect) of the cable pumps excess lubricant up into the speedo head where it gums up the magnetic drum.
Possibly go the route you originally planned. Open up the plastic housing somewhere around the outside edge, towards the rear of the housing. Get a trigger type oil can. Fill it with menthol alcohol. (the non drinking kind) Give the drum and the disc it drives a good flush. The alcohol will clean up the excess oil and evaporate away in a short time. Get some really thin oil. (3m or thinner) Dip a small phillips screw driver or an ice pick shaped tool into the oil and apply sparingly to pivot/turning components inside.
Cover your hole in the housing with duct tape (red-green special)
A drop or two of oil around the odometer numbered wheels would also help after flushing out the inside with alcohol.
A $35.00 bike speedo is always a bonus. I have discovered though if you put one of those on you cannot read the LCD display properly if you wear Polaroid sunglasses.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"
92 ZX11 Temptress

[Dennyz]

Be careful what you flush with. These gauges have light foam pieces inside that dissolve with alcohol. Also make sure that that what ever you use, does not flow on to the face. It is possible to wash debris from the back out front where you can see it. Most solvents (including alcohol) will leave stains on the black instrument face.

Cutting a hole is a great idea and might possible work on the metal housing as well. The biggest challenge will be keeping chips from falling into the gauge and getting them out once they do. If they are not removed, they will eventually find there way to the front. The next thing more frustrating than a gauge that does not work right is a gauge with a foreign object or finger print on the inside.

This has been the biggest problem I have had with opening these gauges up and working on them. That is keeping everything clean when I put it back together. More than once, I have had to take it apart again because of some junk that ends up on the front panel. I vacuum it out best I can, clean the face plate and glass with quality glass cleaner and assemble it very carefully.