My 12' Deep-V Klamath runs 21 MPH with 300# in the boat, 18 MPH with 410#. I run a late model Merc 9.9 two stroke and because I mainly troll I did not want to go bigger. I have had the same boat in the past with a 15 two stroke and it would run right along at 29 MPH but would load-up and smoke...