Speedo problems dax busa.

[chubbsr1]

Yes, it didn't take long for something else to go wrong, although it's not really a major problem.

We I was out in the car for some reason the speedo just started to drop from the proper speed that it was doing, it was registering at 110mph (on private roads officer) then it dropped slowly to 70mph.

Now when accelerating, the speedo does move, but it's miles out from where it should be, it's the standard hayabusa clocks that are in it.

Can anyone tell me what has caused this and how I can fix the problem, I hope it's only a little problem that can be fixed.

any advice appreciated.

thanks

Keith

[liszt]

Not sure how the bike engined ones get the feed for the speedo from.

I know some have magnets glued to the propshaft. One may have been dislodged. Time to trace your speedo cable.

[watsop]

The other type of sensing system uses a sensor, and a big disc with holes in which is mounted on the propshaft. If the distance from the sensor to the disc gets too great or the sensor centreline doesn't align with the hole centrelines as they pass then the speedo readings can get inaccurate.
This misalignment/badly set distance would also be true for the magnet based system I guess but missing magnets is quite a common fault with that kind of system as I understand it.

I had this problem at my SVA and found my sensor was 3mm from my disc and therefore the speedo started to read slower at anything above 50. Once I adjusted it to 2mm all was well.

[busa_rush]

You've lost some magnets ! They are usually on the flangs at the front of the front prop shaft where the drive pins engage with the gearbox output sprocket. Should be three glued on there with aruldite or similar.

You've also probably got a yellow box or the Dax version of that behind the dashboard.

[chubbsr1]

I shall have a look tonight to see where they are missing. do you know where I can get other magnets from to put back in there.

I'm thinking that it's probably when I have taken out the reverse box and put it back in there has been some movement in the front propshaft, as it did work for the first 25 miles, then it just slowed down.

I will have a good look at it tonight and see what's needed to sort it out.

Many thanks

keith.

[pdw709]

I've just (last night) fixed the speedo on my Striker, which was also missing a magnet. Try "Speedy Cables" (www.speedycables.co.uk/).

I had to purchase an entire sensor kit (reed switch, wires and magnets) as my reed switch had blown, but they might be able to sell you just the magnets (they are small rare earth magnets which are very strong - you need to attach them to the prop-shaft or where applicable with epoxy i.e. araldite glue).

Alternatively if you have less magnets you could always try re-calibrating the speedo - as long as the magnets are equally spaced then it should'nt be a problem.

Phil

[chubbsr1]

thanks for the posts, very helpful. I have located the sensor and there is one magnet that is missing.

I have tried speedycables and they don't sell separate magnets for the kit. Does anyone know of any companies that sell just the magnets? I have also tried greengauges but they only sell the full kit.

thanks

[pdw709]

As I mentioned in my post, I got a full set of 6 magnets in my sensor kit. I only used one, and therefore have 5 spare.

Contact me offline ([e-mail]) and I will gladly can send you one free of charge.

Phil