Here"s some advice I was given and it worked great!
On break-in: Run it at variable throttle up to 3/4 under no load for 15 minutes to assure full coolant flow and operation of systems. Then use it for light variable loads for 10 to 15 hours. Change the oil and then just use it as you would but limit full continuous loads to 10 minutes or so for another 10 hours. Then make it pay for itself.
I followed this and the tractor runs great! Also, once the 15 minute warm up period is over have a buddy help you torque the head (110 lbs i believe) and do a valve job. If there is a leak or problem, stop the tractor and at least torque the head bolts warm to get that out of the way then address the other issues. ~Anthony