"Kevin, because of the low tol
"Kevin, because of the low tolerance 4 strokes have with regards to neglect/lack of maintenance - unless someone was practically giving it away, I would not buy a used 4 stroke.
Unless it came from a shop/dealer that provided a warranty of at least 1 year. If you are looking for a potential rats nest of problems, an un-maintained 4 stroke is the way to go....
Similarly, because of the additional maintenance and over double the number of moving parts (which can fail), I would be hard pressed to buy a new 4 stroke - at least as long as there are alternatives.
Lower units are fairly common and if the need ever arose to replace it, I'm fairly certain you could obtain one in fairly short order..."