I have a Craftsman DGT 6000 with a Kohler CV740-0018 27 HP engine. The last time I mowed this past fall I turned off the mower deck and started towards the garage where I keep the tractor I heard a pecking in the engine which quickly turned into a hard knock. I shut the engine off and pushed it into the garage. The next day I puled the engine off and took it apart and found out that it had broken a rod cap bolt, snapped the head off the bolt. There was vey little damage to the block and no damage to the crankshaft so I replaced both rods and reinstalled the engine. It ran good with no vibration or noises. After approximetly 10 hours of operation it is starting to knock again. I haven;t torn it down yet but I expect to find the same thing I have two questions, 1. What in the world is going on. Both time the engine was full of oil and operating at only 1/4 throtttle.2. How do I fix it. This engine has about 240 hours total time on it..