I have a 50HP Tohatsu 2 Stroke, 2007 model, have had 2 only 300 hour services they replace the impellas and plugs, so I keep an eye on the tell tail on the motor replace the plugs every 2 years, spray the engine and all moving parts with lanox, I previously used inox but it did not do the rubbers any good, pull the prop off and grease the shaf at least once a yeart, spray the trailer after use, and always use salt off or a similar product to flush the engine, wipe grease on links in the engine, grease the nipples at least once a year and as I do not take it out as much as I should, I pretty well spray everything after fishing but if I am going out the next day, a engine flush will do. You can spend heaps on servicing but if you have a reputable brand common sense should prevail.