Motor size

[Charles Treichel]

I have an '84 Dory, powered by a 70HP Johnson. Eventually I would like to consider upgrading.to a 4 stroke engine. What would be an appropriate HP rating for the boat considering performance and economy? Would it be a mistake to consider going down to, say 60HP? Would 100HP be to high? How much more more efficient would they be at cruising speed (18-20kph)?
Are there any significant differences between the various brands, Honda, Suzuki, Evinrude, Merc?[/img]

[Salmon Slayer]

Charles:

I had a 112 Johnson 2 stroke on my classic when I bought it and repowered to a 90 hp Suzuki last year and I love it. 4 Stroke is the way to go and as for brand; go with what is serviced well in your area. Honda has carbs and my Suzuki has fuel injection which is the way to go for colder water but really, all the new 4 strokes are pretty reliable.

I cruise pretty heavy because we are often a long way from any provisioning or support and due to rough water I often cruise at 8 - 15 knots; the 4 stroke is quiet, smooth, and fuel efficient at these speeds.

Good luck and please post some pictures of your boat.

Andy

[SEA3PO]

I have twin 40 Yamaha's...on my 22' cruiser...and consider that almost the minimum power for that boat...I know of someone who had a 70hp Suzuki on theirs and traded the motor in on a Honda 90 as they were very disappointed in the performance... I think I would too.... I really like the Honda 90 motors...you might also look at the new Yamaha motors as I was told that they now are also fuel injected..(much better)
If I had my choice again I think I would have more power than the 80hp I have and run the motors at lower speeds (to save fuel)...I average somewhere around 4 to 4.5 miles per gallon and my boat is usually pretty heavily loaded.
You might also look at the new Evenrude motors...I understand they are really fuel misers...but also that they don't like cold water...

Joel
SEA3PO