Replaced speedometer. By fljohnboy (Read 1,491 times)

[fljohnboy]

I have a TaoTao 150 I bought about 6 months ago. Ihave 800 miles on it. It came with the kilometer speedometer. I found a new speedometer MPH on ebay. I replaced the Kilo with the MPH. Was working fine for a couple hundred miles and still works fine up to about 40 but after that, say about 50 or so,it reads like 65-70. Where would I look for the problem, speedometer, cable or something else?

[Deleted]

its probably your speedometer. all of em are known for being inaccurate. mine is off by quite a bit.

[fljohnboy]

I know they're all off. I just went out and put the GPS on the thing and up to 50 it read about 4mph higher then the GPS. What I'm saying take the bike up to about 55 on the gps and speedometer is reading 70 about 15 mph higher.

[Deleted]

it could be just that it is very inaccurate as it goes up and at a certain point it gets worse. ive seen other people with that problem and usually its got to do with the spring inside. theres no fixing it usually except replacement

[catman25]

I replaced mine with a tach .original did not . hooking up tach was easy but now no backlight . idk

If this works with just bulbs or if the screen lights up like the original ??

[jct842]

Some speedometer cables have been known for that sort of thing. What happens is the core needs some lubrication and being spring wound it hangs up for an instant while the lower portion is still turning and winding up, it gets unstuck and the gears inside speedo get an extra kick from the wound cable letting loose. I would pull the core out, clean out the casing good and relube.(and the puck too) I have used white lithium a couple times with good results.


edit: cheap speedometers are seldom totally linear, they read great at one end or half then get progessively worse going toward the other end.
Some makers see this and place the numbers non linearly to compensate too.

edit: The Ideal would be a digital speedometer with an analog read out that could be programed for non linearity, a change in tire size and a end result of a perfectly accurate meter at all speeds.

[dazza]

Had the same problem with my speedo, but being the stock dash. Compared it to gps speed and the analog speedo was out by 7km/h. Bought a new one off ebay for only $55 (AUS) free postage and have had it in for 2yrs. Has been working great and is accurate, at the time of purchase though I had to email the seller and tell them the size of my rims so they can calibrate it. Only problem with it now is if I leave the scooter sitting in the sun the digital part fades away.




Tacho was easy to get working, extended the wire to reach the coil and wrapped the wire around it, works like a charm.

[richardv]

Even my Dodge Dakota has this problem as did my Gold Wings and Magna. It would be nice to get a speed only GPS.

Before those it was full throttle or nothing.

[mxmatt]

May 15, 2014 23:56:08 GMT -6 jct842 said:

Some speedometer cables have been known for that sort of thing. What happens is the core needs some lubrication and being spring wound it hangs up for an instant while the lower portion is still turning and winding up, it gets unstuck and the gears inside speedo get an extra kick from the wound cable letting loose. I would pull the core out, clean out the casing good and relube.(and the puck too) I have used white lithium a couple times with good results.

Thanks for sharing this.  Have you actually seen this correct the notorious problem of speedos being off a bit?  I sort of just accepted that anything above 15 MPH on my speedo is about 5 MPH slower than what it reeds having tested it with a GPS.  IF this is a fix, I'm on it like white on rice.  Your explanation seems very plausible to me. 

[jct842]

A lot of people use a graphite based lube too, but a rough spot on the core or casing will cause this.

[mxmatt]

But have you actually experienced this fixing the problem or is it theory?

[Bashan]

Both of my Bashans read more and more inaccurately the faster you go. At 30 they read 35, but at 50 they read 65. If you get a cheap Sino scooter, it will read like that. Just use a GPS and don't waste your money on an OEM replacement. They all suck. Rich.

[jct842]

No theory, just fact. I have seen countless speedo cables over the years get the cable cleaned and work right just like they were new. The tach on my tractor was jumping around and after the drive cable clean and lube worked fine for maybe ten years, then it snapped off. That sort of thing was common on 40's and 50's cars. Now days they are all electric in cars and most motorcycles.

[mxmatt]

I'm on it. I'll let you know how it goes. Thanks

[FACE PLANT FOR LIFE]

The speedometer on our 2006 Town & Country is pretty inaccurate too. It's good until about 45-50 MPH and then it just loses it (this thing is electronically driven, too, so that's even weirder). At 80 MPH you're only going 72.