Thanks Don 87. I found the problem. The engine was seized due to water entering the cylinders from the exhaust and sitting for two months. I removed the exhaust manifold, towed the tractor with my truck and popped the clutch a couple times to free the engine. After cranking the engine to get rid of all the water and flush with diesel, I reinstalled the exhaust, and voila, she started right up. After warming the engine thoroughly, I changed the oil and filter but could detect no water in the oil. Had I left the tractor sitting for another month, I think I would have had to junk the engine. I thought the shelter I had it under was weather proof. No a bucket will ALWAYS be sitting upside down on the exhaust when not in use. Now I've got to get back to work dragging logs out of my woods.