GSX-R Speedo intermitantly running fast.

It was reading fine after my first attempt but had the odd giddy moment where it would shoot up to 186 or 68 when I was going 30! I then moved the sensor away a few mm and it seemed fine again. Went down to Oulton Park yesterday and it again had a few glitches that seemed to be set off by bumps in the road but was mainly fine. On the way home it was happening more which was a pain.

My only worry is, that I'm assuming the speedo determines how the mileage goes up and so when the speedo goes up to 186 etc the bike thinks I've covered more distance then I have as I was only going 30. I wasn't sure if it was just me but the last 1 mile of my journey my odometer went up by 4 miles and my total journey today of around 100 miles put the best part of 200 miles on the clock!

Checked the sensor when I got back and it hadn't moved and is nice and solid so it's not that. I'm thinking its still the spacing and/or it's reading the other rivets. Just a bit of a pain really but it's also creating false mileage which isn't good. Bikes only on 10,024 now but by rights should be still under 10k.

Any thoughts?

IF its jumping around like that then to me it suggests a false positive, move the pick up further away and try again.
Of course I've never done this/fitted one of those but that would be my understanding of it.

Yeah thats my next move although I don't know how much further I can gt it away. My main concern is the mileage going up quicker than it should. Does what I've said seem right to you that the mileage is determined by the data the speedo sends if that makes sense?

Yeah it does as surely thats the only way the clock will have of telling how fast/many miles you've done. If it's intermittent like that could it not be a loose connection somewhere?

[Nobbylad]

Depending on which sensor you've got, I would say it's a loose connection. My speedo started running erratically exactly like yours and then it just gave up the ghost. I ordered a new Hall effect sensor and when I went to fit it, turns out some of the cable had worn against something and it was shorting until one of the cores became severed. I stripped and re-soldered the cable and it's been fine ever since. If however, your sensor is fubarred, I have a brand new one!

Originally Posted by Nobbylad

Depending on which sensor you've got, I would say it's a loose connection. My speedo started running erratically exactly like yours and then it just gave up the ghost. I ordered a new Hall effect sensor and when I went to fit it, turns out some of the cable had worn against something and it was shorting until one of the cores became severed. I stripped and re-soldered the cable and it's been fine ever since. If however, your sensor is fubarred, I have a brand new one!

The sensor is one of these, http://www.efi-parts.co.uk/index.php?productID=198. I got it of Bibio as he had all the correct connections so he cut it to the correct length and crimped on the connector so I could 'plug and play' so I'd imagine the wiring is fine but I won't rule it out. Where was yours loose at the connector end or at the sensor end? How far off the magnets have you located the sensor, just wondering if I need to move it slightly further away.

After I've had a look if it looks knackered I'll let you know about the sensor cheers.

[Nobbylad]

Chuffing heck that's expensive!

Mine's this one => http://uk.rs-online.com/web/p/magnet...633D4E4F4E4526

Mine was loose about 6 inches from the sensor end as it had rubbed against either the fairings or the tyre...I can't remember which, but it had basically worn through the outer sheathing and one of the wires. I fitted it by stripping back some of the speedo cable, then stripped each of the cores in a staggered fashion, so that once I'd spliced and soldered the cables together, the finished diameter was still the same as the original speedo cable. I'd also slid some heatshrink sleeving on before I'd started the job so that once it was done, you can't really tell there's a connection and it's nice and watertight.

Don't worry don't plan on buying that one was just the first site I came across with the correct picture!

Luckily I'm probably not gonna be out for another proper blast until next weekend so gonna give the sensor and connections a good checking over, make sure magnets are all fine and might even fettle a more substantial bracket just to eliminate any uncertainties. If I do need another sensor, I've seen others use one like this http://www.jameco.com/webapp/wcs/sto...0001_512401_-1 as it can be easily adjusted, but hopefully it won't need to be the case.

[Fallout]

As others have said, definitely a loose connection. My 2000 gixxer in an import with a KPH->MPH scaler between speedo and instrument panel. Connections are dodgy on that, so it often reads zero, but I've had it up to 380mph, which I think is damn good going if you ask me! Removing it gives me reliable speed readouts in KPH. Basically a dodgy connection is likely to be your culprit, imo.