Hello Graham22, Dieselboy, Blue and members,

I think Blue has, as always, given good advice here.
I just want to clarify the purpose of the L.H. washer in the photo.

It's not a washer! It's a seal protector that goes above the boss.
If it is loose on the crankshaft, throw it away.
These alloy protectors were introduced to prevent grass wrapping around the
crankshaft and destroying the seal, thus preventing the scavenging of the fuel mix.

From a service point of view, the Belleville lock washer appears to be un-servicable,
in that it has lost its coned-disc springing properties, and should be replaced.
There also appears to be some damage to the blade holder centre.

Hope this helps.
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JACK.