Well I just got don repairing our 7710 tractor.It had developed a bad internal water leak in the engine.While using the tractor it lost all the coolant in about one hour filling the oil pan.After removing the engine I found a weep hole inbetween the #3 cylinder and the camshaft.The engine always ran good and did not use oil.I repaird it by drilling&tapping the hole .I used a 5/16 set screw and locktite to plug it.I guess the block was a bad casting that went through.I also put 15 P.S.I. of air on the block to check for leaks before reassimbaly.It works fine now.