Hello Sandblaster,
Yes I used a genuine Kawasaki seal with a small amount of bearing fit solution.
Then made a retaining washer on the lathe that went in the shallow recess between the main bearing and the seal. This was measured to ensure there is a 'light squeeze' on the seal once the main bearing was fitted, fully home.
The seal protrudes inwards a small amount once fitted, Note : There is a very small ring of rubber on the circumference edge (the thin edge innermost when fitted) on genuine main seals. This washer pushes against that edge.
I put a few dots of threebond in the recess beforehand to hold the washer in place to stop it bouncing out.
I also notched the washer so a tab bent into the cylinder drain 'groove', That way the washer doesn't rotate thus blocking off that drain hole.
Pressed bearing fully home ... all good.
Thanks