Yamaha, Mercury and Johnsons are all good engines. And you would want an Engine to power your boat and not a motor. As a motor is powered by electricity, an engine is powered by a petroleum product.

I don't think the brand really matters anymore. One is as good as the next. I have asked dealers and they always recommend something but I have to wonder. Are they recommending the one that they make the most money on? Anyway, I have been on boats with 2 stroke motors. ( engines ) My boat came with a 4 stroke. I really like the 4 stroke. No oil tank, no mess, no fuss. However 2 strokes require less maintenance, no oil changes. Mercury recommends an oil change at 20 hours then every 100 hours I think. The 4 is quiet, loads of bottom end torque and gets really good fuel economy. One thing, do not overpower your boat. If 200 is max recomended for your hull, a 150 will probably make you happy. Unless you are racing. Don't buy a V-6 if there is an inline 4 available in the HP you want. ( less weight better fuel economy) Calculate the total weight of your boat. Hull, motor, fuel and max load. Then talk to a dealer about H.P. and props. You want the boat to plane with a good load on board without having to run the poop out of your motor. Once you decide on a new motor, make a deal with the dealer to trade props if yours is incorrect let him recommend a prop. The motor will have a max RPM rating. At wide open throttle, your motor should run close to the recommended max RPM (within 250 rpm or so) but not over. Bottom line, you want the smallest motor that will do the job well.