125-200cc Wr125 front sprocket nightmare

I'm trying to get hold of a new front sprocket for my 2001 wr125. The only one husky list is a 6 spline sprocket thats for models 95-03.
However I have a 12 spline output shaft.......
The old sprocket also has a piece that sticks roughly 4mm proud at the back of the sprocket.
I'm completely stumped as to why my bike has a 12 spline output shaft.
Has anyone got any ideas? I was thinking maybe it's. Cr engine, maybe a newer or older model engine, maybe it's a box from a completely different engine.......

Has anyone come across this before?

They're all like that from 98 onwards mate! Pre 98 is the 6 spline chunky lookin sprocket. They'll be on ebay or local dealer should be able to order one easily enough

Talon part no. TG441 (14t)

the old sprockets are still used on the newer bike models SMS 125 and WRE 125

I have no problem to get both version (in europe)

Robert-Jan

Talon, proX, renthal(maybe), jt(maybe)

In the states JT and Sunstar for sure

Renthal makes one for the 125 as well.