The crankshaft is out of round. Fit bearing at the point when it is tight and keep it on the tight side - where tapping with little hammer is required to move it back and forth.
I measured the "egg shaped" rod bearing journal on the crankshaft (rod number 5) with a micrometer today.
I found out that this journal is worn about 0,02 millimeter (the smallest diameter is about 0,02 millimeter smaller than the biggest diameter), which means it is about 0,0008" out of round.
I understand this is far from ideal.. But in the repair manual it says that "if the journals exceed 0,001" out of round or taper, the crankshaft should be replaced".
Since I am just under 0,001", I hope I might get away with it for a while... At least I will give it a try.