Check out boatdiesel.com for all the info on the motor. With normal care and a few particular areas to watch - namely the raw water pump, this is a very reliable boat motor. Especially in our trawler type boats with easy rpm's you should last a long time. All assumes the P.O. took good care of them and excersised them regularly. Good luck Brian Shanafelt Isobel K 37' Custom Pilothouse (w/Cummins 6BT5.9M) Seattle