New speedo drive but giving me false readings!

Hi all, i replaced the speedo drive on my 2003 SV650s because the plastic lugs were broken in the and the speedo was always reading 0mph. But the problem is, is that now i have replaced it i am getting false readings on the display, when i am doing approximatly 30mph, the reading is saying 60mph. The readings do go up and down relitive of if im speeding up or slowing down but they are way too high. I took the new speedo drive off again and took the plastic part out of it, replaced the broken plastic part in the old speedo drive with the new one and put the old drive + new plastic part on the bike again and i still get the false readings. I would be gratefull if anyone could shed any light on the problem. Thanks, Ross

Some of those speedo drives had 4 magnets in 'em but there seems to be some around which use 8. (not sure when they changed) Obviously you got the wrong one (the one with 8 magnets) and this has doubled your speed reading.

[yorkie_chris]

You have fitted a rotor from a later bike (K5>?) which has 8 poles.

Originally Posted by yorkie_chris

You have fitted a rotor from a later bike (K5>?) which has 8 poles.

+1. K3 and K4 are 4 pole.

i have a similar problem bought an sv650s 2005 had the origional drive but no speedo, bought a new one on fleabay and im getting the same thing it says im doing 60 when im doing 30. is there any way to remove some of the magnets or is it a matter of just buying a new speedo drive