RE: O.S .46LA Head Gasket Help
Here's a couple of pics from an OS61FXrebuild. Differences include the head gasket is set in a recess in the head and there are 6 head bolts.
pic 1 - the loosen and tighten sequence for the head bolts (1 &4, 2 &5, 3 &6)
pic 2 - the head gasket - very thin and easily "kinked".
pic 3 - I use a standard hex wrench - to torque but not over torque I apply pressure with my little finger only - keeps from buggering up cylinder head bolt threads
pic 4/5 - I use a length of fuel tubing to start threading the glow plug into the head - again, so as NOTto bugger the threads in the head.