I would prefer the 300 hp 4 strokes. The 300 hp 2 strokes had issues. Even though a lot of 31 have 225 or 250's that really is not as efficient as the 300's will be. You will find yourself running to high of rpms resulting in an increase in fuel burn with the lower hp motors.
This is the boat my friend went with . Basically 100hp more , a 31 VS 27 ,and 6yrs newer than his old . He got 300 hdpi's . He will run them until they blow up and then repower.
His old 27 got hit by lightning , the engines were smoldering , and the hull had a hole where the lightning went thru.
From what I have read thus far, the new Yammy 300's are great engines, but don't forget that that the pre-2008 31's were not designed/built for the weight of four strokes on the transom.
that is totally incorrect. my 2005 hull was engineered for the 4 strokes. the f-250's were the preferred power package, for the model 31, until just recently when the new yamaha 300 4 strokes became available. a new and most important feature of the v-6 4 strokes is the availability of a key fob. much like a car's ignition key, the motors can not be started without the original key.
This is hilarious, congrats to your friend btw. i made an offer on that same 31 that was in fort myers. Boat was beautiful except for those motors.... Wasn't looking to get into 70k and repower or fix a blown motor..
2008 they introduced the "T" series. the hull was modified somewhat with a negative radius chine extending all the way to the bow. also, if you look at transom, you will notice more of a sharp "V". they moved the console foward and the deck cap was changed among a few other changes. they also enlarged the bilge access. i don't keep up with all the changes, so you may want to call the factory if you are really that interested.