Go by the recommended torque in the manual!! I don't remember off the top of my head, and go in steps.
Maybe #15 first sequence, then go to maybe #25 and the 3rd step arrive @ recommended torque.
Then run it till it is good and warm--operating temp-- maybe 10 minutes or
better if you cut some grass.
then stop, turn it off and let it cool, have lunch/dinner and retorque to recommended torque.
Better if you can come back the next day for the final re torque,
but if you can hold your hand on the head, it is cool enough to retorque.
That should take care of the cylinder head gasket leak.
You will observe that the bolts have loosened after it cools down, that is why they need re torquing.
