On Tue, 27 Jun 2006 06:26:31 GMT, "padeen"
wrote:

Please don't take my word as fact; I'm not really a very knowledgable small
engine mechanic, but I think one screw is idle and the other is power
(cruising rpm).

AND, there is some danger in running an engine too lean as
it runs hotter and can burn rungs. If it won't run anywhere else, check the
air filter.

I will. Thanks for the suggestion.

Also, a jet that will run best only closed is a worn jet.

Could be...

That six horse Evenrude sure gave some service. I ran it for three years,
probably 3hrs a day for 150 days a year, then sold it to a friend who got
another six years from it as a spare.

That's reassuring!

Its biggest problem was that the top
"bearing" wasn't a real bearing; just sleeved in the aluminum block. When
it got older the shaft would wobble, causing the points to become inaccurate
and the motor to start hard and run lousy. Still worked, though.

The other problem was that the Yukon was heavily silt-laden so we'd go
through a water pump rebuild kit every year.

Hmm.. I have that problem too... the water I canoe in is not clear but
somewhat muddy.

Still, if I can even get one or two years of life out of it, it will
have been worth the money I paid. It certainly seems ideal for my
purposes.

I'm thinking of building a bracket that will sit the motor directly
behind, and in-line with the center-line of the boat -so no steering
compensation will be required.

Al D

I never found steering compensation a problem with a side mount. The main
problems with rigging the motor off the stern are thus:
* It's harder to reach the motor for adjustment, pulling up, fiddling with,
or shutting off.
* It puts the motor's weight that much further back from the center of the
canoe, requiring more ballast to compensate for it.
* There's more structural rigging, adding more weight.

If you do try this route, I'd suggest arms back to a flat piece for the
motor coming from pivots on the gunwhales, with some form of adjustable
stops to vary the prop's bite. Any more of the motor down into the water
beyond the anti-cavitation plate increases its drag exponentially.

Personally, I think the side mount would work fine, and be a good deal less
trouble, but this world is built on "bad" ideas that turn out to be
earth-shatteringly effective!

Brad Snow
s/v Aldonza



"Al D" wrote in message
...
On Tue, 27 Jun 2006 06:26:31 GMT, "padeen"
wrote:

Please don't take my word as fact; I'm not really a very knowledgable
small
engine mechanic, but I think one screw is idle and the other is power
(cruising rpm).

AND, there is some danger in running an engine too lean as
it runs hotter and can burn rungs. If it won't run anywhere else, check
the
air filter.

I will. Thanks for the suggestion.

Also, a jet that will run best only closed is a worn jet.

Could be...

That six horse Evenrude sure gave some service. I ran it for three years,
probably 3hrs a day for 150 days a year, then sold it to a friend who got
another six years from it as a spare.

That's reassuring!

Its biggest problem was that the top
"bearing" wasn't a real bearing; just sleeved in the aluminum block. When
it got older the shaft would wobble, causing the points to become
inaccurate
and the motor to start hard and run lousy. Still worked, though.

The other problem was that the Yukon was heavily silt-laden so we'd go
through a water pump rebuild kit every year.

Hmm.. I have that problem too... the water I canoe in is not clear but
somewhat muddy.

Still, if I can even get one or two years of life out of it, it will
have been worth the money I paid. It certainly seems ideal for my
purposes.

I'm thinking of building a bracket that will sit the motor directly
behind, and in-line with the center-line of the boat -so no steering
compensation will be required.

Al D

On Tue, 27 Jun 2006 22:45:45 GMT, "padeen"
wrote:

If you do try this route, I'd suggest arms back to a flat piece for the
motor coming from pivots on the gunwhales, with some form of adjustable
stops to vary the prop's bite.

Adjustable stops seems a definite good idea.

Any more of the motor down into the water
beyond the anti-cavitation plate increases its drag exponentially.

I wasn't aware of that. Thanks! The cavitation plate (such as it is)
on this little motor is directly above the prop, so if I only just
submerge the plate, the prop will only be about 3" below the
surface... At the moment, I have it set at about 13" below the
surface. Less efficient, perhaps, but it does make the whole
motor+boat more stable (less top-heavy).

Personally, I think the side mount would work fine, and be a good deal less
trouble, but this world is built on "bad" ideas that turn out to be
earth-shatteringly effective!

A side mount is what I now have. I built it a few days ago from teak
offcuts and tested it at the weekend. It does work, but I have to
surmise that the setup is not as efficient as it would be if the prop
was behind the stern, aimed along the boat's center line. Obviously,
that's because when the prop is off to one side, it's going to be
expending some proportion of its energy in trying to make the boat
turn towards the opposite side. I guess a quick fix (but not an
efficient one) would be simply to clamp the motor-mount bracket on
slightly skew, so that the direction of the prop is aimed slightly
inwards of dead-ahead.

I suspect the effort in building an in-line motor mount would be quite
a money-saver in the long-run, since gasoline costs about $8.50 a
gallon over here.

Unfortunately, as you pointed out, there would be some safety and
comfort issues in that the controls on the motor will be much harder
to reach (unless I remove the rear seat so I can move right back into
the stern when using the motor). But that may not be a good idea
beacause I think the seat may be needed to brace the hull.

So perhaps I'll just leave things as they are (for now, at least).
Paying a few pennies more for gasoline, per trip, is not a big deal,
after all. And I am, at least, getting good overall speed from the
side-mounted motor (seemed like about 15 knots to me - with the bow
out of the water).

Regards,

Al Deveron

" - with the bow out of the water)."

Remember, the speed (efficiency) of the hull is directly related to its LWL;
I think you'll lose more efficiency (gas) with your bow in the air than w/
the sidemount. Bringing the bow down can be affected by adjusting the angle
of attack of your motor and redistributing your weight. On the Yukon it was
very unusual to see a 19' Grumman squarestern WITHOUT a 5gal gas can on its
foredeck.

Brad





"Al Deveron" wrote in message
...
On Tue, 27 Jun 2006 22:45:45 GMT, "padeen"
wrote:

If you do try this route, I'd suggest arms back to a flat piece for the
motor coming from pivots on the gunwhales, with some form of adjustable
stops to vary the prop's bite.

Adjustable stops seems a definite good idea.

Any more of the motor down into the water
beyond the anti-cavitation plate increases its drag exponentially.

I wasn't aware of that. Thanks! The cavitation plate (such as it is)
on this little motor is directly above the prop, so if I only just
submerge the plate, the prop will only be about 3" below the
surface... At the moment, I have it set at about 13" below the
surface. Less efficient, perhaps, but it does make the whole
motor+boat more stable (less top-heavy).

Personally, I think the side mount would work fine, and be a good deal
less
trouble, but this world is built on "bad" ideas that turn out to be
earth-shatteringly effective!

A side mount is what I now have. I built it a few days ago from teak
offcuts and tested it at the weekend. It does work, but I have to
surmise that the setup is not as efficient as it would be if the prop
was behind the stern, aimed along the boat's center line. Obviously,
that's because when the prop is off to one side, it's going to be
expending some proportion of its energy in trying to make the boat
turn towards the opposite side. I guess a quick fix (but not an
efficient one) would be simply to clamp the motor-mount bracket on
slightly skew, so that the direction of the prop is aimed slightly
inwards of dead-ahead.

I suspect the effort in building an in-line motor mount would be quite
a money-saver in the long-run, since gasoline costs about $8.50 a
gallon over here.

Unfortunately, as you pointed out, there would be some safety and
comfort issues in that the controls on the motor will be much harder
to reach (unless I remove the rear seat so I can move right back into
the stern when using the motor). But that may not be a good idea
beacause I think the seat may be needed to brace the hull.

So perhaps I'll just leave things as they are (for now, at least).
Paying a few pennies more for gasoline, per trip, is not a big deal,
after all. And I am, at least, getting good overall speed from the
side-mounted motor (seemed like about 15 knots to me - with the bow
out of the water).

Regards,

Al Deveron

On Wed, 28 Jun 2006 16:21:07 GMT, "padeen"
wrote:

Remember, the speed (efficiency) of the hull is directly related to its LWL;

As I understand it, that applies to displacement hulls. However, my
canoe has a flat bottom, making it technically a semi-displacement
hull which has some lifting capacity and therefore the ability to
exceed its maximum displacement speed. Otherwise, I don't think I
could have got it up to the 15 knots I estimate I was doing the other
day.

I think you'll lose more efficiency (gas) with your bow in the air than w/
the sidemount.

You may be right. I have no idea.

Bringing the bow down can be affected by adjusting the angle
of attack of your motor and redistributing your weight. On the Yukon it was
very unusual to see a 19' Grumman squarestern WITHOUT a 5gal gas can on its
foredeck.

I'll have to do some experimenting..

Thanks again,

Al Deveron

Al Deveron wrote:
On Wed, 28 Jun 2006 16:21:07 GMT, "padeen" wrote:

Remember, the speed (efficiency) of the hull is directly related to its LWL;

As I understand it, that applies to displacement hulls. However, my
canoe has a flat bottom, making it technically a semi-displacement
hull which has some lifting capacity and therefore the ability to
exceed its maximum displacement speed. Otherwise, I don't think I
could have got it up to the 15 knots I estimate I was doing the other
day.

Were you using the Evinrude for a power source to hit 15 knots?

Steve
--
Steve Cramer
Athens, GA

On Thu, 29 Jun 2006 20:31:16 -0400, Steve Cramer
wrote:

Were you using the Evinrude for a power source to hit 15 knots?

Let me put it this way: I certainly wasn't *paddling* at 15 knots in
my 14 ft canoe!

Al Deveron