The earlier 25's were rigged with the Honda 130, which is a smaller engine than the 135 (on the 150 block), and a bit bigger than the 115. This boat on e-bay has the Merc 115, and probably might be one sold by Lake Union, since they were Merc dealers. In my opinion the 115 is not enough engine for the 25. I had the 130 and it was barely enough when the boat was fully loaded for cruising in AK. (We did a number of trips in the boat, including the Delta trip, A Catalina cruise, Broughtons and a month in Alaska. So the boat with a 130 is capable,but it would be rare for us to get 20 knots---most of the time we were at 17 to 18 knots. That is fine, but you don't have a lot of reserve. We might have gotten more with a different prop. When we sold the boat, it was to Hooked on Powell, and he ended up with an 11" pitch prop (as I recollect), to get the boat to perform properly at Powell. We run our boats heavy with supplies on board for 6 weeks, including generator, refer, freezer, dinghy, dinghy motor, etc.
If you were to keep the boat stripped down, and use it mostly for fishing you could get by with a 115, but not with the boat loaded for cruising.
You cannot tell a lot by looking at photos, but the boat on e-bay is well equipped, however, I don't see the seat back for the forward seat, and there are a few issues which pop out looking at the photos, such as a number of rust stains. It is a 2004, with the holding tank aft--not photos of the cockpit and that is where there maybe floor or transom issues. The one photo of the GPS shows the boat South of Monterey, CA. offshore If you are interested in the boat, I would look at it very carefully and get a good survey. For $25,000 you can repower sell that 115 Merc and get a larger engine or try it like that, and fix any issues you find, assuming that the hull is OK. However, there may be a reserve on the boat. My guess is this is a repo.