while cutting engine started smoking badly. shut off the engine and later found most of the oil had apparently burned out through the exhaust. I can turn the engine less than one turn by hand. felt like maybe something inside the engine is broke. the oil level was filled to normal. the smoke was greyish white. the mower is twelve yrs. old with many hrs. it has been well maintaned. is it possible a ring broke and will not let the engine turn freely? my wife was operating the mower at the time so this is her story. im just trying to figure out if its worth takeing it apart or not. what is the estmated life for a 17 hp. inteck ohv engine. any help would be appreciated. thanks