well i am going down the rabbit hole a little deeper, after trying to figure out the crank shaft will not rotate all the way. split tractor and have the engine out checking on the front main and back main bearings. there is a lot to look over trying to determine the problem. first thing was the washer in the front cylinder that cracked the piston then after hand cranking engine with the front pto it would not fully rotate. and after pulling engine and removing the front of timing gears gov and the fuel injector pump the crank would turn over no problem. also the thrust bearing on the back side of block had a four piece metal flange that held the bearing in place the bottom inside flange had been rubbing on the counter weight ,i could see where it had heated up the castiron on the weight. not sure that was the problem after pulling the injector pump the crank turned freely. do you kubota guys have any thing else i should look for or ideas that i could be missing? also my mentor said this engine design is similar to the offenhauser race engine from the early days of racing the way the main bearings were built into the block.
