Speedo challenges - K3 naked

Hi All,

My speed suddenly stopped reading a few weeks ago, found the mashed rotor and replaced it, but no joy.
Obtained a used "pointy sensor and rotor" unit and the speedo now works.............unfortunately its reading about double the actual speed
Any (constructive) views?
Also I read about peeps using a Haynes test sequence for the speedo sensor and wiring, can anyone supply the necessary test details as I don't want to throw out the old sensor unit if its just a wiring fault?

Thanks in advance

Leigh

Just to assuage your fears that it might have been a curvey one they sent, I have a curvey one fitted to my pointy, it reads correctly, and doesn't fit without bodging. So it will be a correct one if it fitted perfectly. I had other woes but no double speed woes so can't help much further.

[BillyC]

Hi Baldy, long time no see!

I'm having problems with my speedo at the moment too, but not quite the same. I'm reading something like a constant 186mph at times... and then everything between there and zero.

The test outlined in the Haynes manual, is the same test that is outlined in the K3 Service Manuals (Section 8 - Electrical System). If you don't have a copy, I can email one to you... but they are downloadable on a Bit Torrent site somewhere. For some reason they were removed from the main Org site.

It simply involves powering the Hall circuit in sensor, and connecting a voltmeter to the signal wire so you can observe the signal as you rotate the wheel. In your case, it's well worth doing. See page 38.

To overread by twice the speed, the sensor rotor would have to be magnetically polarised twice as much I would have thought - for the sensor to produce twice the number of pulses.

Have you tried your new rotor, in your old sensor?

Thanks Warthog, thought my implied "worry" might have been too subtle for the Org

Thanks Billy,
REALLY should get back up to Soho or has the meeting place changed? I also need to take a look for rideouts as well
The new rotor/old sensor produced zilch.
I was tinkering with the idea of trying the new rotor in the 2nd hand sensor, so I guess that's tonight sorted then
It is REALLY is weird as I'm guesstimating that the speedo over reading by 100% !!
Thanks for the guidance on the tests. I do have the manual so I'll look it up. Cheers for the offer

[Stu]

Calling Northwind!
Sure he posted (regarding the GSXR swap replacment Veypor speedo sensor) that the latest Pointies required twice as many magnets ( as earlier Pointies.
So effectively your new speedo sensor is recoding twice as much as your old (sorry!) bike is expecting

[BillyC]

Originally Posted by Stu

Calling Northwind!
Sure he posted (regarding the GSXR swap replacment Veypor speedo sensor) that the latest Pointies required twice as many magnets ( as earlier Pointies.
So effectively your new speedo sensor is recoding twice as much as your old (sorry!) bike is expecting

As far as I'm aware, the speedo sensor has not changed between the curvy and pointy SV models. It's the same 4 bladed rotor, giving 4 pulses of the supply voltage for ever revolution - or one pulse every 90 degrees.

Northy's Veypor sensor is just the same thing, but smaller, affixed to the rear wheel...

I prepare to be corrected!

[BillyC]

Originally Posted by Baldyman

REALLY should get back up to Soho or has the meeting place changed? I also need to take a look for rideouts as well.

Yes, you should
We tend to be up in Soho Square more often these days, on account of the PC nobfeatures and his clan of parking "attendants".

[northwind]

Some of the SV Rider guys with more recent SVs have found that 8 magnets are needed. There's a change in part number on the speedo drive as well. So, strange as it seems they do seem to have gone over to an 8 trigger speedo, though I've never seen one in the flesh.

billyc


not meaning to be cheeky but could you email me a copy of the service manual please

Originally Posted by BillyC

Hi Baldy, long time no see!

I'm having problems with my speedo at the moment too, but not quite the same. I'm reading something like a constant 186mph at times... and then everything between there and zero.

The test outlined in the Haynes manual, is the same test that is outlined in the K3 Service Manuals (Section 8 - Electrical System). If you don't have a copy, I can email one to you... but they are downloadable on a Bit Torrent site somewhere. For some reason they were removed from the main Org site.

It simply involves powering the Hall circuit in sensor, and connecting a voltmeter to the signal wire so you can observe the signal as you rotate the wheel. In your case, it's well worth doing. See page 38.

To overread by twice the speed, the sensor rotor would have to be magnetically polarised twice as much I would have thought - for the sensor to produce twice the number of pulses.

Have you tried your new rotor, in your old sensor?

Fitted new rotor to the 2nd hand sensor and all is well in the garage
The 2nd hand rotor had been marked with white paint on one of the rotors, so I will scrape it off sometime and just try it to see if it was this that caused the "double speed" readings