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Hello
The right excenter is ziro with the swing arm, but the left one is not, look at the photo.
Any recommendation?

check if the excenter sits correctly on the splines

The axle is splined at both ends , however there is one spline missing on each end of the axle ( looks like one extra wide spline) , there is a corresponding missing spline in each excentre ,the idea being that the excentres will only fit onto the axle in one position which keeps the axle square and level in the swing arm. If you dont get these splines correctly alligned the excentre wont go fully onto the axle. Sometimes a previous owner ( its never the current one ) being unaware of the spline allignment issue simply forces the excentre onto the axle, this can damage the excentre ( cuts the missing spline in the excentre ,as mine was ) . Fortunatley any miss alignment is easily spotted if you assemble the excentre , axle and swing arm without the wheel. If you check for square in both horizontal and vertical planes. If indeed the excentre has been forced its not a big issue , no new parts needed , you just have to check for correct allignment ( eyeball will do when you know where to look ) every time you reassemble the axle/excentre/wheel .
Hope this helps
Hamish

I haven't got eccentric adjusters but that's a really nice explanation Hamish. I can picture them perfectly.

Found two of this together After the Excenter.
After some digging found thet the missing one come After the sporckt.
So there is one Before and one After the sporckt.
Now everything is O.k.