Wow! That's a lot of play axial play!
I don't know how much different your 216 is to my 261, but the main thrust bearing holds the crank in place axially.
I would check into this pronto before running it too much, you could really putting some undue work, wear and stresses on the crank, rods cylinders and pistons!
Someone else pipe in and tell me if I'm wrong please!
Jerry
