Speedo Went Wacko!

Old Guy Too Many Bikes

Old Guy Too Many Bikes

Well-Known Member
Went for my usual weekly ride today on my '82 CT70 and my speedo wacked out. Up to about 30 mph it's fine, but as soon as I got faster the needle got very optimistic. At about 35, it was reading about 45 and at I'd guess 45 it went past the odometer and almost back around to the zero stop. When I'd slow down and stop, it went back to zero. At 40-45, it also bounced around a little. The bike's got almost 7000 original miles. The odometer is still correct and the cable isn't binding or anything. Is it worth taking apart and trying to fix? Anyone have a similar experience. The '82 has the small round speedo.
 
K

ktheake

Active Member
I believe CJ may have the correct idea about the calibration spring coming off the magnet . It is located at the base of the needle - coming off the magnet .
You can't be certain unless you open it up and then it's a fragile piece to begin with and probably unserviceable .
What if since its working - maybe just a stiff cable inside the sheathing and its just binding up and then just gives a false high speed as it let's go of the bind buildup . Possibly just remove cable and clean then lube and reinstall would be my hopefull initial call .. cost is nothing but time .
 
red69

red69

Well-Known Member
I've had something similar with my S90. Remove the speedo and shoot some WD40 in the back of the unit where the cable resides. Allow the crap to drain on a piece of paper towel, speedo face up so it doesn't foul the face. I suspect my problem was dried grease.
 
Old Guy Too Many Bikes

Old Guy Too Many Bikes

Well-Known Member
The cable and sheath are in good shape, I've regularly lubed it over the years. I've watched a few youtube videos, where something inside catches the drum and affects the needle. Also the WD40 idea is something I may try. I once took apart one off an early CT90 to clean the face and lens, and although I got it back together, it wasn't pretty. Thanks for all the responses, I'll have a go on it tomorrow.
 
kirrbby

kirrbby

Well-Known Member
red69 said:
I've had something similar with my S90. Remove the speedo and shoot some WD40 in the back of the unit where the cable resides. Allow the crap to drain on a piece of paper towel, speedo face up so it doesn't foul the face. I suspect my problem was dried grease.
Click to expand...

I've always been afraid to put any oil, etc into a speedo. Afraid it will "foul the face".
I'd be careful with the wd40...then maybe allow it to drip out, then add some more appropriate lube. I THINK white lithium is recommended for speedos...but I'm not sure about that.
I would like to get ALL of my speedos lubed...but I think I need a little...maybe clarification...on how to do that correctly, and without causing harm.
Anyone in the know, please comment. How? How much? And what kind? Please.
 
OLD CT

OLD CT

Well-Known Member
You nailed it Kirb. Typed in speedo lube on yotube and found a guy restoring a speedo on a bmw, He uses white lithium grease TUBE not spray sparingly. That took 1 minute to find/watch and if I was real serious, I would watch more than one video. LOL!
 
Old Guy Too Many Bikes

Old Guy Too Many Bikes

Well-Known Member
Pulled the speedo today and heard a rattling inside. Turns out the bulb shell had come loose and was interfering with the drum rotating. Took my handy needle nose pliers and twisted that thing out of there. Problem is solved, speedo works perfect, although I no longer am able to put a bulb in there. Since I never ride the thing at night, it's no big deal. Thanks for all the advice anyway, good to know.
 
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