If that was a Yamaha 2-stroke (non-Enduro), then it weighs 79lbs and is a very good and light engine. It also weighs exactly the same as the 2-stroke 15hp.

If it is the Enduro 9.9, then it weighs 85lbs - also about the same as the equivalent Enduro 15hp.

Either way, he was kind of silly for not getting a 2-stroke 15hp instead. I also wonder about what, if any, warranty he received.

Mark