For what it's worth, I have a Honda 7.5 hp (4 stroke)that I have had for over 25 years. All I have ever done is change the oil and spark plugs occasionally. Starts first pull every time. Four strokes are nice as they are much more quite than a two stroke. In my 16 ft aluminum you can carry on a conversation with the guy in the front seat without hollering.(while trolling) Also, no mixing gas . Good Luck.