Changing Your Outboard Motor Oil
Most manufacturers recommend changing your outboard motor oil and filter after every 100 hours of use or every season, which ever comes first. Some people may postpone this task, but it is essential if you want to prolong the life of your boat and achieve optimal performance. Changing your oil may seem daunting, but with a few wrenches and some knowhow, you can get the job done in no time.
Always remember to drain all of the old oil before refilling the crankcase. Mixing old and new oils will leave deposits in the system and limit the effectiveness of the new oil. Also, be sure to add a quart of oil for the new filter and run the engine when you are done to ensure that the oil pressure is correct and there are no leaky areas.