Speedometer calibration on 77gl1000

[Hondarebel]

I have a 77 gl1000 with 79000 miles. I felt I was riding slower than the speedometer reading. Confirmed when my GPS read a constant 10 miles per hour less than the speedometer. I read how to change the speedometer cable. But can anyone tell me how to adjust / calibrate for an accurate reading. Thanks

[virgilmobile]

I'm not aware of any calibration methods on a mechanical spedo....It's operated by spinning a magnet in a cup attached to the needle...All the parts are "fixed solid" to the framework...
I have cleaned and lubed the internals of one that did help a bit but the end result was poor..The chrome ring is removed to separate the case...
I did replace the spedo....It too was off by +5mph...

[Hondarebel]

Im sure its due for a good cleaning. I doubt it has ever been cleaned. I am the 3rd owner. Thanks for the infoon your situation. I guess I could get a new one. Im sure it wouldnt hurt.
Thanks again.

Safe riding

[pistolpete]

Hondarebel,
Typically the instruments have leaked the silicone from the dash pot. This is very viscose and can slow the movement.
We can help with this by opening the gauge, cleaning the movement and recalibrating it to the correct ratio.
Let us know if we can help.
Pistol Pete
Oldwings.com

[Hondarebel]

Pistolpete, thanks for the info.
Does what you describe also cause the speedometer to register a speed faster than the actual? Example: speedometer=60 mph, GPS=50 mph.
I'm sure it needs thorough cleaning. Is there a link / description of the process?

Havnt attended to it yet. Been working on timing belt replacement.
Thanks
Hondarebel

[pistolpete]

Usually a fast movement will be the result of other internal problems.
If you like we can take a look at it.
Most movements can be calibrated if the movement is OK.
Pistol

[virgilmobile]

Maybe I should elaborate on my post.
Can a spedo be calibrated.?? Well yes and no.
The "no" is aimed at the casual mechanic,like me.
I just have this problem with tiny clock springs and counterweights.
Theres no dials,screws or knobs to turn for calibration.

The "yes" is for the tech that has the necessary stuff to delicately align and calibrate it.
I'm in the "no" bracket and Pistol is obviously in the "yes" bracket.

The "no" costs nothing..the "yes" will.

What's the going price range for a restoring spedo.?

[pistolpete]

Email me at petesgl@comcast.net and we can work out the details.
Typ. The base price is $95.00.
Pistol

[virgilmobile]

I just never knew that you did this kinda work.
Sounds like the cost of having it done right is about the same as getting a used one with the same problem.

Nice to know.
See what happens when your posting bout stuff?
We learn something new every day.

[pistolpete]

I just never knew that you did this kinda work.
Sounds like the cost of having it done right is about the same as getting a used one with the same problem.

Nice to know.
See what happens when your posting bout stuff?
We learn something new every day.

Yes we do and we are able to open, repair and close them quite effectively.
We hope you all with give us a chance to help.
Pistol

[aussiegold]

Pete,
are you able to re vamp a speedo that displays symptoms of self destruction ? the needle started wavering like flag in the breeze , accompanied by a screaming from the unit, something akin to a fireworks shooting off. getting louder and louder, until i had the presence
of mind to undo the cable , therefore preventing the the thing from blowing up in my face. ( it was bloody hot too)
this happened at 120 klms per hour, on my way to a vintage motorcycle race meeting. i would have stopped but i had not had a beer for seven hours and i was in a bit of a hurry. ( oops, i digress )
ps.
its a klms per hour unit . history unknown.

[pistolpete]

Aussiegold,
Sorry for not getting back to you sooner.
The answer to your question in two fold.
1) Yes it can be repaired and even fixed.
2) While I don't wish to turn down work, it may be more in your interest economically if you try to locate another unit that works properly. If the trip odometer requires resetting we can help.
We will try to be of service any way you wish, just let us know.
Pistol