Nice job on the air tunnel paint job Geert, Tidy! as they say over here.

Yes, tidy ! This engine is fine, so it was worth spending some time and money to it to tidy it up.

The other engine is te actual problem, but I might have a solution yet .
I just wonder why I need two spare engines
Just for fun having them I think

We only ran it up and down the road, in the middle of winter.
So I guess the thickness of the oil at the moment was covering it up.

This morning I took the engine further apart .
The play on the piston rod is 2 mm ! on the other side there is no measurable play, not measurable with a calliper but you can feel a play when pulling the rod away from the crankshaft.
I still can't understand why we did not notice this before.