I'm looking at purchasing a used pontoon boat. The boat itself is 17 years old, but my only concern would be the engine. It has a 125 hp mercury 2 cycle engine, but I'm not sure if it's original to the boat. I've never owned a boat before, so would greatly appreciate any pointers anyone has or things to look for and/or questions to ask specifically about the engine. The dealer who has it says that they go through the engine and perform any required maintenance and tune-ups before putting it up for sale. They offer a 90 warranty with purchase.