K3 speedo sensor (another speedo thread)!

Here's another speedo drive/sensor question for everyone.

Basically, I trashed my K3 front end and then bought a front end off a K7 as a replacement, including the speedo sensor. I've heard that K4 onwards the speedo-sensors are different - to do with the magnets (8 polarities vs 4 I think?) - and if I were to fit the K7 speedo drive to my K3 it will read double the speed.

I've checked out the existing speedo sensor and it's knackered, however I was thinking that if I get hold of a K3 speedo sensor and take out the middle part (see pics) and put it in the K7 sensor, it should read everything fine.

Is this correct? Feel free to use lay-man terms because I am a complete newbie when it comes to this stuff.

[Bibio]

as far as i know the only difference between the drives is the magnet rotor. this causes a lot of confusion as the complete units are the same part number for all years its the magnets that are different part numbers.

the part number of the magnet you want is:

34983-21E00

Is that the middle part as shown in the pic?

Couldn't find the part using that code however I've found someone on here selling the complete speedo-sensor unit from a K3 for £20, so just going to get that then swap the rotors out, cheers for your help yet again Bibio!

bibio my good man you are a helpful sort but i find it easier to sell the person the part than mess them about with part numbers

Check your pm's dave

have done bruv getting posted tomorrow 4 u

Cheers mate!