I would like to know what is the right size motor for a 17-ft
fiberglass center console. The parameters a

- The combined weight of the boat plus motor will be
around 1,900-lb.

- There will be 3 men and 1 woman on the boat (around
600-lb).

- I will run the boat in fresh water lakes or
in protected sea water (inshore or bay).

- I expect to run the boat at 20-mph cruising speed
(land mile, not nautical mile). I don't do skiing.
I only use the boat for fishing.

I would like to know how small a motor I can use to satisfy the
requirements stated above. I understand that fiberglass center console
boats in that size tend to have a 90-hp or 115-hp outboard motor. But I
also understand that most people like to run their boat in a very high
speed (like 35 mph or 45 mph) that I don't enjoy doing. I am thinking
of downsizing the motor to match the relatively low cruising speed that
I likely will run the boat at.

Based on past discussion, I am under the impression that an outboard
will work the most efficient if it is being run in wide-open-throttle.
This means I am looking for a motor that can satisfy the requirements
stated above when it is being run in wide-open-throttle (instead of
getting a BIG motor and then running it at low speed).

Thanks in advance for any info. And hope people don't mind the fact
that I have asked a similar question previously.

I posted a similar message not so long ago about matching a motor with
a 18-ft aluminum boat. But I have changed the requirements (18-ft
downsized to 17-ft, aluminum changed into fiberglass, ...etc).
Therefore, I need to ask around here again. Moreover, my wife wants to
run the boat in sal****er from the get go instead of phasing in from
freshwater into sal****er (as what I have originally planned).
Therefore, I need to get the right gas engine from the very beginning
instead of using a small kicker engine to get by.

Jay Chan

wrote ...

Based on past discussion, I am under the impression that an outboard
will work the most efficient if it is being run in wide-open-throttle.
This means I am looking for a motor that can satisfy the requirements
stated above when it is being run in wide-open-throttle (instead of
getting a BIG motor and then running it at low speed).

You may want to rethink running wide open at cruising speed. Reliability will
suffer and fuel consumption wont be significantly better than a moderate sized
motor running at 70-80% of full throttle.

-rick-

First thing I'd look at which nobody else has mentioned yet is the Max
HP rating for the boat on the transom plaque. Then decide between 2 or
4 stroke. That's how I'd approach this - I wouldn't necessarily go with
the biggest motor the boat is rated for either.

On 18 Oct 2005 08:58:50 -0700, "
wrote:

First thing I'd look at which nobody else has mentioned yet is the Max
HP rating for the boat on the transom plaque. Then decide between 2 or
4 stroke. That's how I'd approach this - I wouldn't necessarily go with
the biggest motor the boat is rated for either.

I had a 70hp on a 15' Whaler CC. It was the perfect size for that boat, as long
as I had three or less people aboard. Once I got to four or more, the boat took
much longer to get on plane, and the engine seemed to strain.

On a 17' CC, I'd want a 90hp minimum.
--
John H

"All decisions are the result of binary thinking."

Based on past discussion, I am under the impression that
an outboard will work the most efficient if it is being
run in wide-open-throttle. This means I am looking for
a motor that can satisfy the requirements stated above
when it is being run in wide-open-throttle (instead of
getting a BIG motor and then running it at low speed).

You may want to rethink running wide open at cruising speed.
Reliability will suffer and fuel consumption wont be
significantly better than a moderate sized motor running
at 70-80% of full throttle.

Thanks for the correction. I must have misunderstood other people
advice. OK, I will have to assume that I will be running at 2/3
throttle most of the time instead of at WOT. I am glad that you have
corrected me before I wasted my money on motor that is under powered
and have to be run at WOT all the time.

Jay Chan

By definition, efficiency would be when the boat is on plane, trimmed
out and running without effort. That is not at WOT throttle - more
often it's at 2/3s throttle. On my Ranger for example (it's the
closest boat I have to a 17 foot Center Console) it comes up fully on
plane around 3,000 rpm at 20 or so mph and settles in (same throttle
setting) at 4100 rpm and 30 mph. WOT on this boat is 5500 rpm and 45
mph. At cruise (4100 rpm/30 mph) it eats very little fuel - I can run
all day at that speed. The engine is a 200 hp Evinrude FICHT.

Thanks for the correction. 2/3 throttle is what I will aim at.

You run your 200HP motor at 2/3 throttle to achieve 30 mph. Does this
mean that I will need something like a 150HP motor at 2/3 throttle to
achieve 20 mph? I have an impression that yours is a bass boat, and
bass boat tends to have a very oversized motor. Therefore, I need to
discount that to get back to something more appropriate for a center
console.

Seem like I need to check the maximum HP rating of the boat and not
going to much below the max. rating. The other alternative is to see
what the manufacturer offered in their boats. If the max is 150HP and
the highest HP of the motor that they bundled with a boat is 115HP, I
would assume that 115HP is fine and not need to go for a 150HP motor.

I know that you are attempting to lessen the economic impact of a boat
purchase, but at some point, it makes no sense. The monetary
difference between a used 40 horse and a used 90 horse isn't that
significant. Considering the engine load you states (people, gear,
fuel) I would consider 90 hp the bare minimum.

Yes, saving upfront cost is a major consideration. The other
consideration is not to spend more than required. But if higher
horsepower is required to get the boat on plane reliably with 4 persons
on board, I will have to get a higher horsepower.

Yes, the price of a used motor seems to have a lot to do with how old
it is instead of how powerful it is.

Does your 90 HP minimum have taken into the account of 600-lb of
men/woman on board? If 90HP is good enough, I will have more selections
of motors available instead of being narrowed down to only 115HP.

Jay Chan

First thing I'd look at which nobody else has mentioned yet
is the Max HP rating for the boat on the transom plaque.
Then decide between 2 or 4 stroke. That's how I'd approach
this - I wouldn't necessarily go with the biggest motor the
boat is rated for either.

Thanks for mentioning about the max hp rating of the boat, and I will
not likely to go for the max either.

I will likely also take into account of the range of motor size that
the manufacturer has bundled in their boats. If they are offering the
same boat with both 90HP and 115HP. I will need to make sure I will not
go below their range of motor sizes too far, or better yet just stick
with their minimum motor size (in this example, that will be 90HP).

Jay Chan

I had a 70hp on a 15' Whaler CC. It was the perfect size for
that boat, as long as I had three or less people aboard. Once
I got to four or more, the boat took much longer to get on
plane, and the engine seemed to strain.

On a 17' CC, I'd want a 90hp minimum.

I assume that we can get a 17-ft boat on plane quite well with a 90hp
motor as long as we only have one or two persons on board. This also
means that 90HP will not be enough for a 17-ft boat if I have four
persons on board. Because of the fact that I like to have three or more
persons on the boat, this means 90HP is not enough then, and I will
have a problem getting the boat on plane. Sound like I will need a
115HP motor, and stop thinking about 75HP, 90HP motors.

OK, 115HP will be IT!!

Thanks for sharing your experience. This surely helps me to narrow down
the selection very quickly.

Jay Chan

I will likely also take into account of the range of motor size that
the manufacturer has bundled in their boats. If they are offering the
same boat with both 90HP and 115HP. I will need to make sure I will not
go below their range of motor sizes too far, or better yet just stick
with their minimum motor size (in this example, that will be 90HP).

As mentioned in another message, I think I had better to get a 115HP
instead of a 90HP -- seem like 90HP is only good for no more than 2
persons on a 17-ft center console and I expect 4 persons to be on the
boat.

Jay Chan

On Tue, 18 Oct 2005 21:35:48 GMT, Shortwave Sportfishing
wrote:

On Tue, 18 Oct 2005 17:30:10 -0400, Harry Krause
wrote:

Shortwave Sportfishing wrote:
On Tue, 18 Oct 2005 17:17:43 -0400, Harry Krause
wrote:

Shortwave Sportfishing wrote:
On Tue, 18 Oct 2005 17:06:29 -0400, Harry Krause
wrote:

Shortwave Sportfishing wrote:
On Tue, 18 Oct 2005 16:29:08 -0400, Harry Krause
wrote:

wrote:
I will likely also take into account of the range of motor size that
the manufacturer has bundled in their boats. If they are offering the
same boat with both 90HP and 115HP. I will need to make sure I will not
go below their range of motor sizes too far, or better yet just stick
with their minimum motor size (in this example, that will be 90HP).
As mentioned in another message, I think I had better to get a 115HP
instead of a 90HP -- seem like 90HP is only good for no more than 2
persons on a 17-ft center console and I expect 4 persons to be on the
boat.
Take a long look at the Yamaha 115 four cycle. It's a hell of a mill.
Go with a 90 ETEC - you'll get the same performance as the Yamaha 115
four smoke for less money and you'll save in the long run on gas.
Documentation?
http://www.evinrude.com/en-US/HomeVideo.htm

http://www.evinrude.com/en-CA/Campaigns/

Enough said four smoke boy. :)
And this has what to do with a comparison between a 90 hp Evinrude and a
115 hp Yamaha?

Simple enough. Out of three relatively equal types of engines all
with equal horsepower, the clear advantage was to ETEC.

Thus, the evidence would seem to show that a 90 ETEC was clearly
superior to a 115 hp Yamaha four smoke because it's lighter, quieter,
more efficient and probably faster both out of the hole and top end..

Heh, heh, heh.... :)

Four smokes are doomed - ETEC is the wave of the future!!!

Damn...you must moonlight for the Bushed Administration.

Not really.

But I will confess to having partaken of the Bombardier Kool Aid. :)

mmmmmmbombardierkoolaidmmmmmmmmm

LMAO!
--
John H

"All decisions are the result of binary thinking."