Proper break-in of your engines is critical to a long life. Break-in requirements vary by model and manufacturer so be sure to read and understand the specifics for your engine. As a general rule, the first 100 hours are most important. During this period you should operate your engine at heavy loads with minimal idling. Also, be sure to vary your speed regularly.
Many manufacturers use a straight weight oil during break-in to control wear and allow components to properly seat which should result in maximum performance and engine life. For example, many Northern Lights engines require a break-in oil change at 50 and 100 hours while some John Deere models require it first at 100 hours. When changing your oil during this period and for the life of the engine, be sure to use oil that meets or exceeds the factory recommendations.
Other break-in service may include an initial 100 to 600 hour valve adjustment and/or injector bolt torque. Check your engine mounted zincs for accelerated wear and set up a maintenance schedule accordingly. Your transmissions may require an initial service including gear oil and filter change as well as suction filter cleaning, and linkage adjustment, tightening, and lubrication.
During break-in pay close attention to your engine, check your fluid levels regularly and look, listen, and feel for any hardware that may have vibrated loose. When planning this initial maintenance, don’t forget wing engines and tender outboards. These items may also require a proper break-in and due to their low hours are usually neglected.