Mercury - FourStroke 300 Hour Maintenance Kit 4-6hp Service Package Precision Components 8M0120836. Overview. If you run a small outboard, you know exactly how much it carries on its shoulders. These little engines are the ones pushing dinghies through quiet coves, powering small fishing boats toward early-morning bites, and helping families explore the shoreline one slow drift at a time. They may be compact, but when you depend on them, you depend on them completely. And there is a certain comf