i have 50 yamaha 2 stroke and is very quiet and has alot of torque. i test drove a 50 4stoke and it was no comparison. it was just a little quieter idleing but just as loud on top end. the 2 stroke will throw you back in the seat while the 4 stroke was real sluggish to go. on the top end the 2 stroke is a couple mph's faster. i usually carry abunch of guys w/ me hunting/fishing and i had a 30 2 stroke, but it didn't have the hole shot i needed. the 50 2 stroke was definetley what i needed.