Originally Posted by Bluejacket7377
Thanks, SailingUphill, for your reply - it is useful information.
Your experience tends to make me believe that my Super 40 Plus Seagull is probably more toward the 3.5 hp end of the stated range rather than the 2.5 hp end of the state range.
The significance of this is that I probably need the thrust that can be produced produced by a 3.5 hp motor.
From the previous quote "A Bollard pull test showed that the Mercury 3.5hp and
Tohatsu 3.5hp were the most powerful at 90lbs of thrust...", I'd conclude that I need about 90 lbs of thrust.
Also, from the same quote I note "...the Suzuki 2.5hp at 83lbs of thrust...", which is almost equal to the two 3.5 hp motors, but is the same weight (30 lbs) as the Seagull.
So I am tentatively concluding that the Suzuki DF2.5 is what I need to get.
Thanks again for your help.
Power is power, and thrust is thrust. You're not going to get 3.5 hp performance out of a 2.5 hp motor. The laws of physics prevent that. There's no true substitute for higher power.
At a given power, you can tweak the thrust of a motor by selecting a different prop pitch, but it will always come at the expense of other performance factors. You can pick a prop that will deliver more thrust when the boat is moving slowly (typically a lower pitch prop), but suffer poor fuel economy and/or poor top speed in extended cruising use (due to over-revving). Sounds like that may be the tradeoff you're looking for. Just be aware that it's always a tradeoff, and that you'll sacrifice one factor to improve another one.
Typical motor size for a boat your size would be 3.5-6 hp.
I have the Suzuki DF2.5 on my dinghy. Overall I am happy. I like that it has a true neutral gear instead of the Honda's centrifugal clutch that can grab suddenly when you're starting the motor. I like that it's water-cooled and thus quieter than the Honda. I like that it weighs only 29 lb. I think that for some applications, 360 degree steering is better than a reverse gear because the prop is always turning in the direction it's designed to have the most thrust, so you may stop better than with a reverse gear would at the same hp.
For the Suzuki, I'd recommend always burning the gas out of the carb if you're going to leave it more than a couple days. I often go further and siphon the gas out of the tank first, then burn off the carb. The main customer complaint for this motor is from poor fuel delivery due to debris/varnish clogging the tiny fuel passages. I'm not sure it's any worse than any other small hp motor. The little motors always are finicky with debris. I have not had that problem, but I'm just barely getting started with my motor.
I'd recommend buying your motor from a brick & mortar dealer, not online. You may need the support, and if you shop around you can get just as good a price. My Suzuki was about $50 less from the dealer than the big Suzuki online outlet.