I have a few questions about oil. Since the service manual lists almost every possible weight of engine and front gear case oil acceptable for the 650, it must come down to operating temperature to determine the weight to use. It is going to get colder here in Iowa and I plan on using 10w30 in the engine and front gear case. What are you people using in the engine and front gear case. The rear gear case oil is a no brainer since mobil 424 is the only choice. ps. Jeff start a 650 Prairie Yahoo group so we all can chat via e-mail. Just a thought. Terry