Originally Posted by c21fishing
looking to buy a 2003 4 stroke 75 hp merc , do know much about them , what is maintence like more or less the a 2 stroke . better or worse ?
You will just need to change crankcase oil and filter, probably just once a year. Best to do it as part of your winter layup winterizing process. You Wont have to keep feeding it oil all year like a 2 stroke,so for the most part it's just a tradeoff. You also might get longer life from your sparkplugs on the 4 stroke.
Periodically you are supposed to have the valve clearance checked and adjusted but I don't know if anyone is doing that much. I have had 2 different mechanics tell me that any time they ever check them they never seem to need any adjustment. My 4 stroke is 11 years old, I have never checked it. Still runs like it always did. Will probably check the condition of the timing belt and seek advice from my guy this year.
Otherwise, like any outboard, need to change lower unit oil every season, and periodically change out a fuel filter and the water pump impeller. So overall I would not call it either better OR worse.Just a little different. Don't be afraid of it. Overall You will likely enjoy a 4 stroke.