Posted by BrOnS on 02/01/10 - 4:15 PM
#1
I just recently purchased a 1986 17.5 ft whaler. The boat came with a 40hp 4 stroke suzuki outboard. I knew the engine was rather small for the boat when I bought it, but for the price I couldn't resist. My question is there anyway to get a better response out of the motor? ie. changing the prop, etc. The motor is at 5,000 RPM's just to get the boat on plane and it's not that great. I called a couple boat dealers and they told me I should be running a 115hp minimum...Was wondering if maybe I could get away with a 75hp-90hp motor. The boat will mainly be used for diving and light trolling if that helps. Any advice would be great. Thanks.
Edited by BrOnS on 02/01/10 - 4:19 PM
Posted by goldstem on 02/01/10 - 6:30 PM
#2
depending on usage a 40 might be okay, I've run a number of 17's with 50 (including a 50 four stroke suzuki, related to your motor).
get a smaller pitch prop so that it will spin close to 6k rpm. probably a pitch of 10 or 11 inches (the 50 ran a 12 inch pitch). with just you in it you should get close to 25mph wide open.
Posted by Joe Kriz on 02/01/10 - 6:36 PM
#3
You might also be better off if you tell us what model Whaler.
A Classic hull is 16 feet 7 inches so I assume this is not the model you are talking about. This model has a max rated HP of 100.....
What is a 17.5 Whaler? Please let us know.