225hp outboard faster than 250hp?

[dennishoddy]

I believe Mercury uses engine computer programming for the different horsepower ratings on the Verado outboards. Yamaha also does it with their big four stroke SHO outboards. I think all it takes is a reflash or maybe a chip to jump from 225 to 300hp. Modern four stroke technology but I prefer the older high winding two strokes.

Your spot on. Onboard computers can change everything to add or decrease HP.
Even non computer tricks.
For example, a few years back, I was looking at compact tractors in the 30-40 hp range.
Since I'm anal about details, went further into the specs.
The 35hp diesel Massy was $700 more than the 32 hp.
Difference? They bumped up the fuel pump pressure to get the extra hp.
Same engine just different fuel pressures to gain a couple hundred rpm that equaled more hp.