Never had one but looking at a boat with a 2020 Merc 250 4S. I have bought enough 2 strokes to know what to look for when buying used. Is there anything special anyone looks for when testing and looking at a 4S engine?

If its a 2020 you should have at least 2 years left on the original warranty (assuming its transferable) as they come with a 3 year unless the original owner bought an extension. Other than that at a minimum take it to a mercury service point and have them pull the computer info for performance ie revs etc and any fault codes.

It’s a year old. Look for scratches on it, I guess. It’s newer than the coffee mug I’m drinking out of.

If you want to be extensive you could get the lower unit pressure tested, get the motor compression tested, and computer read out. As said though, it will have warranty or it should. I would spend the extra to get the max warranty available and as long as it did good on a test drive I would go for it. I would possibly try to negotiate the warranty into the deal

Thanks for the feedback and it looks like it's the standard fair for purchasing a boat. It does have the 2 years of warranty left.

I know its only a year old but this particular boat buying experience has been interesting and I wanted to make sure I wasn't missing anything on a 4 stroke.

I looked at a 2019 Nitro z20 and was close to purchasing it at a dealer. I saw something at the last minute and climbed under the boat and found the Hamby's busted and a hole in the hull. I could stick a 10 gauge wire through the hole, there was also a large deep 3" long scratch (well into the fiberglass scratches) and whatever happened had also broken a hole through the Hamby's. You could only see it laying under the boat. The dealer swears he had no idea and offered to put a new Hamby on and would use the glue to seal the hole. I walked out because he told me that's how they were going to fix it.. Most of the sales people at the dealerships I have been to were a joke and knew very little about boats. I guess that's the new world we live in.

Sounds about right for a Nitro