Outboard recommendations for a San Juan 21
 

Hey Bruce,

You've got alot good replys already, so I'll be brief..

When my Catalina 22's 10hp longshaft died, I replaced it with a shorter
shaft 5hp Merc. Cost was a consideration, I was starting a vacation and I
quickly bought the cheaper motor at the local west marine.

I got the short shaft partly because I wanted a motor that could also use on
a dingy for another boat. I simply remounted the Catalina's outboard bracket
down 4".

If the San Juan 21 is similar to my boat, 5hp is plenty. A bigger engine
would just run at a lower throttle at hull speed and eat through your gas
can faster. As for spinning the prop in choppy seas, My big 10hp longshaft
evinrude 2-cylinder did that too. Sometimes it's just safer to use your
sailing skills than to depend on that egg-beater dangling from the rear.


Please post a follow-up and tell us what you choose.

John.


"Bruce" wrote in message
...
I need to buy an outboard for my San Juan 21 and not quite sure about how
big to go. I would like a 4 stroke and I am thinking that about 5 HP
would
be a good size. Any comments about the different brands would be
appreciated.
Also, do I really need a "long shaft" motor. With the motor mount
currently
on the boat, it seems to me that any motor would easily bury the prop.

Regards,
Bruce

Outboard recommendations for a San Juan 21
 

"Ferg" wrote...

I got the short shaft partly because I wanted a motor that could also use on
a dingy for another boat. I simply remounted the Catalina's outboard bracket
down 4".

Be careful when you do that! You may end up immersing the head and "drowning"
the engine when the transom goes down!

Granted, an outboard on the transom of a sailboat is a compromise at best. When
you cut corners for cost, though, you may end up in a dangerous situation. Just
make sure you know the boat's and motor's capabilities, so you don't end up with
a dead engine when you need it most

Outboard recommendations for a San Juan 21
 

Chris,

You mention that you could always get your boat up to hull speed
before
you hit maximum throttle rpm's. Now, was that in calm waters or going
downwind. I think you will find trying to make headway into a strong
wind and sea puts more demand on the engine. It's for those unusual
conditions that I would be willing to put up the extra cash to get the
reserve power. My only regret is that they have not come up with a
four stroke engine with a reasonable weight. I could heist my 65 pound
Chrysler Sailor over the transom into the boat, at sea. I cannot do
that
with my 4 stroke 99 pound Yamaha. I would have gotten a 2 stroke but I
am tired of mixing the oil with the gas, the loud noises from the
engine,
plus the worry that the government is going to put some kind of
restrictions on 2 stroke engines.
There are places to economize in boating, but for anyone doing
serious cruising (not day sailing), the added expense of a strong engine
is worth it. As I mentioned before, the higher gear ratio gives you
more leeway to increase your thrust, beyond what changing the propellor
can do.
It's true that high gear ratio engines are getting harder to find,
but not impossible.
Two years ago, while on a vacation to the Florida Keys, I found that my
Chrysler had
frozen up in storage beyond repair. I had to hustle to get a Yamaha
dealer to truck
one down from Miami since there were none available locally. I'm sure
that if people
are not pressed for time like me, they can order any engine they want.
If people were
more knowlegable about sailboat engines, they would not get stuck with
these motor boat
engines, and wouldn't have to change props as an afterthought.

Sherwin

Chris Edmonson wrote:

Sherwin;

True enough that gear ratio is of import but I think in the dollar range I
have seen people willing to spend a $150 propeller change will get more for
the expense than the $700 to $1500 sometimes charged for gear change. The
retail marine motor business is spotty at best. Often someone looking for a
particular motor will find that particular motor difficult to obtain. I
have even had people look into changing a short shaft motor into a long
shaft motor along with a gear change... just not cost effective. I guess I
was thinking more of someone wanting to correct a situation with an existing
motor than getting a new one.

Motors are set up for the different kinds of jobs they do. A work boat will
typically have the "high thrust" version whereas a sport fishing boat often
goes for speed / troll trade-offs. A sailboat that cannot plane does not
need a high pitch prop (equates to higher end speed in a planing hull).

Assuming that their gear ratio will allow them to get enough thrust
with
more conventional pitch props.

The
rule of thumb is that for every inch of pitch change you will increase or
decrease your max rpm's by 150 tp 200 rpm (a fact that is written on the
Mercury propeller box). For fuel economy you might choose a lower pitch
that will make power at a lower rpm... in a way this IS a gear change. On
my own sailboats I have gotten hull speed long before I ever get to max
thrust of the motor. It has allowed a smaller motor to be used and saved on
the expense and wieght of the larger motor and the fuel savings on a long
use of the motor. This last is relatively unimportant because in a season's
use I can count the tanks used on one hand!

Because the high thrust option is needed to extend even further the range of
useful power generated by the engine it is reasonable to make a motor with a
MUCH higher gear ratio... so in terms of designing a workboat or sailboat
motor it is understandable that the gear ratios are offered. It is just
that they are not readily available everywhere. There are charts at almost
all marine motor dealers that match pitch to a variety of motors so there
isn't really much experimenting to do to get the power you are seeking.
Overall I have to agree with pretty much everything you say BUT in terms of
expense and availability I would look at my motor with the idea that unless
I were replacing the whole thing I would opt for a pitch change before I
would get hung up on getting a motor that may not be obtainable at the
moment. Your points are very well taken though and if you can find the gear
ratio option it is an easy cure for the thrust question.

There are no easy cures. Changing the pitch to overcome a design
deficiency
is asking for trouble down the line.


Best;
Chris

"Sherwin Dubren" wrote in message
...
Hi Chris,
Your point about the 4-strokes developing power (or torque) at lower
rpm's
than 2-strokes is correct, but I'm not sure that leaves the gear ratio's
out
of the picture entirely. First of all, why would Yamaha and Mercury go
to higher
gear ratio's on their 'high thrust' engines, if it would be simpler to
just change
the propellor pitch to achieve the same result? Secondly, I would be a
little
nervous about experimenting with a propellor's pitch to match it
optimally to
the engine. The bottom line is will a 4-stroke engine with a low gear
ratio
and a compensating pitch propellor run as well as a 4-stroke with a
higher
gear ratio engine with it's appropriate propellor (I don't think so).
Actually,
both the higher gear ratio and the propellor can each contribute to the
higher
thrust. However, given a choice, I would go with the higher gear ratio
which
would allow me to get even more thrust by decreasing the propellor
pitch. With
the lower gear ratio engines, I can only lower the pitch of the
propellor which
has obvious limits as to how much this can be done.

Sherwin Dubren

Chris Edmonson wrote:

All good points being made here. If the wieght maximum you have in mind
is
clear to you then go with a smaller four stroke. I have found it
difficult
to move much more than fifty or sixty pounds of bulky motor around so
would
tend to go with a smaller motor than a lot of folks might choose. The
other
thing is that the four strokes make power at a lower RPM so may be best
on
fuel economy over the long run. The gear ratio is perhaps not as large
an
issue as it was when almost all of the motors were two strokes that
needed
the higher RPM's to get you going. The propeller's pitch can give you
some
of the pushing power that the old gear ratio change would give. If you
don't have enough umph move down a couple of inches in pitch and gain
power
earlier in the curve. The four strokes definitely handle this change
very
well.

Best;
Chris

"Bruce" wrote in message
...
I need to buy an outboard for my San Juan 21 and not quite sure about
how
big to go. I would like a 4 stroke and I am thinking that about 5 HP
would
be a good size. Any comments about the different brands would be
appreciated.
Also, do I really need a "long shaft" motor. With the motor mount
currently
on the boat, it seems to me that any motor would easily bury the prop.

Regards,
Bruce

Outboard recommendations for a San Juan 21
 

Hi Ferg,

I feel badly being the 'critic' here on some of these replies, but
they
really go against my experiences with sailboat engines at sea.
As far as long shaft vs. regular length engines, I have been in
choppy waters
where the long shaft was just about in the water at a wave crest and
almost buried
at the waves low point. A shorter shaft engine would have either come
out of the
water at the high wave or have been swamped at the wave low point. If
you are
sailing calm waters all the time (never happens for most people), you
don't need
the long shaft.

Ferg wrote:

Hey Bruce,

You've got alot good replys already, so I'll be brief..

When my Catalina 22's 10hp longshaft died, I replaced it with a shorter
shaft 5hp Merc. Cost was a consideration, I was starting a vacation and I
quickly bought the cheaper motor at the local west marine.

I got the short shaft partly because I wanted a motor that could also use on
a dingy for another boat. I simply remounted the Catalina's outboard bracket
down 4".

If the San Juan 21 is similar to my boat, 5hp is plenty.

That depends on the weight of his boat. A lightweight trailerable
boat has
less power requirements than a fixed keel heavier counterpart.

A bigger engine
would just run at a lower throttle at hull speed and eat through your gas
can faster.

I thought running at lower throttle uses less gas.


As for spinning the prop in choppy seas, My big 10hp longshaft
evinrude 2-cylinder did that too.

You probably had the engine height set too high for the longshaft.


Sometimes it's just safer to use your
sailing skills than to depend on that egg-beater dangling from the rear.

Yes, if you are willing to run with the wind, or 'heave-to', but if
you want
to make directional headway to get somewhere's, the engine is your
best bet.

Please post a follow-up and tell us what you choose.

John.

"Bruce" wrote in message
...
I need to buy an outboard for my San Juan 21 and not quite sure about how
big to go. I would like a 4 stroke and I am thinking that about 5 HP
would
be a good size. Any comments about the different brands would be
appreciated.
Also, do I really need a "long shaft" motor. With the motor mount
currently
on the boat, it seems to me that any motor would easily bury the prop.

Regards,
Bruce

Outboard recommendations for a San Juan 21
 

Outboard recommendations for a San Juan 21
 

Hi again Bruce,
Just some general observations on the replies to this posting. People
seem
concerned about low cost alternatives, which is fine if you are doing
day sailing
or out on small lakes. However, if you plan to be on any large lakes or
oceans for
any extended cruising, don't cut corners on a good engine. Don't forget
that you
life may depend on it, and that's worth a lot of money. It's true
sailboats have
more options than power boats, but it helps to have a strong dependable
engine
to get you out of the tougher situations. I would recommend a long
shaft, and
in addition, I would recommend a more flexible motor mount that would
allow you
to raise and lower the engine while on the water. If your boat is light
weight
and you plan to do day sailing on small lakes, the 5 hp would certainly
push
your boat fine. Otherwise, I would be looking in the 7 to 10 hp range,
depending
on the type of engine (you could get by with 7 in a four stroke). Also,
go for
the higher gear ratio, if you can find it.

Sherwin

Bruce wrote:

I need to buy an outboard for my San Juan 21 and not quite sure about how
big to go. I would like a 4 stroke and I am thinking that about 5 HP would
be a good size. Any comments about the different brands would be
appreciated.
Also, do I really need a "long shaft" motor. With the motor mount currently
on the boat, it seems to me that any motor would easily bury the prop.

Regards,
Bruce

Outboard recommendations for a San Juan 21
 

I, too, am in a quandry about replacing the 1989 Mariner 9.9 kicker on
my Mac25. I've named the engine "Sybil" due to its several
personalities, one of which involves dying in order to test my
seamanship at the most intersting moments imaginable.

Anyway, I'm interested in a 4-cycle for quiet operation, and I want the
smallest, lightest engine that will push my boat at its hull speed of
6.7mph reliably and safely under varied conditions. You would think
that there would be some scientific way to figure this out, but nobody
seems to know for sure.

SZ


Sherwin Dubren wrote:
Chris,

You mention that you could always get your boat up to hull speed
before
you hit maximum throttle rpm's. Now, was that in calm waters or going
downwind. I think you will find trying to make headway into a strong
wind and sea puts more demand on the engine. It's for those unusual
conditions that I would be willing to put up the extra cash to get the
reserve power. My only regret is that they have not come up with a
four stroke engine with a reasonable weight. I could heist my 65 pound
Chrysler Sailor over the transom into the boat, at sea. I cannot do
that
with my 4 stroke 99 pound Yamaha. I would have gotten a 2 stroke but I
am tired of mixing the oil with the gas, the loud noises from the
engine,
plus the worry that the government is going to put some kind of
restrictions on 2 stroke engines.
There are places to economize in boating, but for anyone doing
serious cruising (not day sailing), the added expense of a strong engine
is worth it. As I mentioned before, the higher gear ratio gives you
more leeway to increase your thrust, beyond what changing the propellor
can do.
It's true that high gear ratio engines are getting harder to find,
but not impossible.
Two years ago, while on a vacation to the Florida Keys, I found that my
Chrysler had
frozen up in storage beyond repair. I had to hustle to get a Yamaha
dealer to truck
one down from Miami since there were none available locally. I'm sure
that if people
are not pressed for time like me, they can order any engine they want.
If people were
more knowlegable about sailboat engines, they would not get stuck with
these motor boat
engines, and wouldn't have to change props as an afterthought.

Sherwin

Chris Edmonson wrote:

Sherwin;

True enough that gear ratio is of import but I think in the dollar range I
have seen people willing to spend a $150 propeller change will get more for
the expense than the $700 to $1500 sometimes charged for gear change. The
retail marine motor business is spotty at best. Often someone looking for a
particular motor will find that particular motor difficult to obtain. I
have even had people look into changing a short shaft motor into a long
shaft motor along with a gear change... just not cost effective. I guess I
was thinking more of someone wanting to correct a situation with an existing
motor than getting a new one.

Motors are set up for the different kinds of jobs they do. A work boat will
typically have the "high thrust" version whereas a sport fishing boat often
goes for speed / troll trade-offs. A sailboat that cannot plane does not
need a high pitch prop (equates to higher end speed in a planing hull).


Assuming that their gear ratio will allow them to get enough thrust
with
more conventional pitch props.

The

rule of thumb is that for every inch of pitch change you will increase or
decrease your max rpm's by 150 tp 200 rpm (a fact that is written on the
Mercury propeller box). For fuel economy you might choose a lower pitch
that will make power at a lower rpm... in a way this IS a gear change. On
my own sailboats I have gotten hull speed long before I ever get to max
thrust of the motor. It has allowed a smaller motor to be used and saved on
the expense and wieght of the larger motor and the fuel savings on a long
use of the motor. This last is relatively unimportant because in a season's
use I can count the tanks used on one hand!

Because the high thrust option is needed to extend even further the range of
useful power generated by the engine it is reasonable to make a motor with a
MUCH higher gear ratio... so in terms of designing a workboat or sailboat
motor it is understandable that the gear ratios are offered. It is just
that they are not readily available everywhere. There are charts at almost
all marine motor dealers that match pitch to a variety of motors so there
isn't really much experimenting to do to get the power you are seeking.
Overall I have to agree with pretty much everything you say BUT in terms of
expense and availability I would look at my motor with the idea that unless
I were replacing the whole thing I would opt for a pitch change before I
would get hung up on getting a motor that may not be obtainable at the
moment. Your points are very well taken though and if you can find the gear
ratio option it is an easy cure for the thrust question.


There are no easy cures. Changing the pitch to overcome a design
deficiency
is asking for trouble down the line.


Best;
Chris

"Sherwin Dubren" wrote in message
...

Hi Chris,
Your point about the 4-strokes developing power (or torque) at lower
rpm's
than 2-strokes is correct, but I'm not sure that leaves the gear ratio's
out
of the picture entirely. First of all, why would Yamaha and Mercury go
to higher
gear ratio's on their 'high thrust' engines, if it would be simpler to
just change
the propellor pitch to achieve the same result? Secondly, I would be a
little
nervous about experimenting with a propellor's pitch to match it
optimally to
the engine. The bottom line is will a 4-stroke engine with a low gear
ratio
and a compensating pitch propellor run as well as a 4-stroke with a
higher
gear ratio engine with it's appropriate propellor (I don't think so).
Actually,
both the higher gear ratio and the propellor can each contribute to the
higher
thrust. However, given a choice, I would go with the higher gear ratio
which
would allow me to get even more thrust by decreasing the propellor
pitch. With
the lower gear ratio engines, I can only lower the pitch of the
propellor which
has obvious limits as to how much this can be done.

Sherwin Dubren

Chris Edmonson wrote:

All good points being made here. If the wieght maximum you have in mind

is

clear to you then go with a smaller four stroke. I have found it

difficult

to move much more than fifty or sixty pounds of bulky motor around so

would

tend to go with a smaller motor than a lot of folks might choose. The

other

thing is that the four strokes make power at a lower RPM so may be best

on

fuel economy over the long run. The gear ratio is perhaps not as large

an

issue as it was when almost all of the motors were two strokes that

needed

the higher RPM's to get you going. The propeller's pitch can give you

some

of the pushing power that the old gear ratio change would give. If you
don't have enough umph move down a couple of inches in pitch and gain

power

earlier in the curve. The four strokes definitely handle this change

very

well.

Best;
Chris

"Bruce" wrote in message
...

I need to buy an outboard for my San Juan 21 and not quite sure about

how

big to go. I would like a 4 stroke and I am thinking that about 5 HP

would

be a good size. Any comments about the different brands would be
appreciated.
Also, do I really need a "long shaft" motor. With the motor mount

currently

on the boat, it seems to me that any motor would easily bury the prop.

Regards,
Bruce

Outboard recommendations for a San Juan 21
 

Hi Steve,
See my reply at the end of this group of replies. Unfortunately, the
engine manufacturers have not solved the problem of a lightweight engine
in the horsepower range you need, say 7 to 10, at least that I know of.
You did not mention why it had to be lightweight. I assume that was so
you could take it into the boat, if necessary, at sea. In my case, I
felt
the advantages of a four-stroke outweighed it's disadvantages of heavy
weight.
I just hope I never tangle a line in the prop or break a propellor
connector
at sea in a storm, since I cannot lift my 9.9 Yamaha over the transom
into
the boat (it weighs 99 pounds and would be at an awkward angle). The
exact horsepower you need is a function of your boat's weight, windage
profile, etc. I would say to get something a bit stronger than you
might
think necessary, as you may need that extra power someday. Burning a
bit
more gas is a small penalty to pay for safety. If your present 9.9
two-stroke
is pushing the boat ok, I would say that a possibly a 8 or 9.9
four-stroke
with the right propellor (low pitch) would do the job. My 9.9 Yamaha
4-stroke
is their 'high thrust' model, designed for heavy displacement hulls, and
has
a low pitch prop together with a high gear ratio to insure plenty of
push
when you need it. With a 25 footer fixed keel boat, I would personally
go
with the 9.9 hp. Strangely enough, Yamaha's 9.9 h.p. high thrust weighs
a bit
less than their 8 h.p. high thrust (both are 4 strokes). If you are
patient
enough, there will be lighter weight versions coming out, but not
knowing
what is on the manufacturer's drawing boards, it's anybody's guess when.

Sherwin Dubren


Steve Zweigart wrote:

I, too, am in a quandry about replacing the 1989 Mariner 9.9 kicker on
my Mac25. I've named the engine "Sybil" due to its several
personalities, one of which involves dying in order to test my
seamanship at the most intersting moments imaginable.

Anyway, I'm interested in a 4-cycle for quiet operation, and I want the
smallest, lightest engine that will push my boat at its hull speed of
6.7mph reliably and safely under varied conditions. You would think
that there would be some scientific way to figure this out, but nobody
seems to know for sure.

SZ

Sherwin Dubren wrote:
Chris,

You mention that you could always get your boat up to hull speed
before
you hit maximum throttle rpm's. Now, was that in calm waters or going
downwind. I think you will find trying to make headway into a strong
wind and sea puts more demand on the engine. It's for those unusual
conditions that I would be willing to put up the extra cash to get the
reserve power. My only regret is that they have not come up with a
four stroke engine with a reasonable weight. I could heist my 65 pound
Chrysler Sailor over the transom into the boat, at sea. I cannot do
that
with my 4 stroke 99 pound Yamaha. I would have gotten a 2 stroke but I
am tired of mixing the oil with the gas, the loud noises from the
engine,
plus the worry that the government is going to put some kind of
restrictions on 2 stroke engines.
There are places to economize in boating, but for anyone doing
serious cruising (not day sailing), the added expense of a strong engine
is worth it. As I mentioned before, the higher gear ratio gives you
more leeway to increase your thrust, beyond what changing the propellor
can do.
It's true that high gear ratio engines are getting harder to find,
but not impossible.
Two years ago, while on a vacation to the Florida Keys, I found that my
Chrysler had
frozen up in storage beyond repair. I had to hustle to get a Yamaha
dealer to truck
one down from Miami since there were none available locally. I'm sure
that if people
are not pressed for time like me, they can order any engine they want.
If people were
more knowlegable about sailboat engines, they would not get stuck with
these motor boat
engines, and wouldn't have to change props as an afterthought.

Sherwin

Chris Edmonson wrote:

Sherwin;

True enough that gear ratio is of import but I think in the dollar range I
have seen people willing to spend a $150 propeller change will get more for
the expense than the $700 to $1500 sometimes charged for gear change. The
retail marine motor business is spotty at best. Often someone looking for a
particular motor will find that particular motor difficult to obtain. I
have even had people look into changing a short shaft motor into a long
shaft motor along with a gear change... just not cost effective. I guess I
was thinking more of someone wanting to correct a situation with an existing
motor than getting a new one.

Motors are set up for the different kinds of jobs they do. A work boat will
typically have the "high thrust" version whereas a sport fishing boat often
goes for speed / troll trade-offs. A sailboat that cannot plane does not
need a high pitch prop (equates to higher end speed in a planing hull).


Assuming that their gear ratio will allow them to get enough thrust
with
more conventional pitch props.

The

rule of thumb is that for every inch of pitch change you will increase or
decrease your max rpm's by 150 tp 200 rpm (a fact that is written on the
Mercury propeller box). For fuel economy you might choose a lower pitch
that will make power at a lower rpm... in a way this IS a gear change. On
my own sailboats I have gotten hull speed long before I ever get to max
thrust of the motor. It has allowed a smaller motor to be used and saved on
the expense and wieght of the larger motor and the fuel savings on a long
use of the motor. This last is relatively unimportant because in a season's
use I can count the tanks used on one hand!

Because the high thrust option is needed to extend even further the range of
useful power generated by the engine it is reasonable to make a motor with a
MUCH higher gear ratio... so in terms of designing a workboat or sailboat
motor it is understandable that the gear ratios are offered. It is just
that they are not readily available everywhere. There are charts at almost
all marine motor dealers that match pitch to a variety of motors so there
isn't really much experimenting to do to get the power you are seeking.
Overall I have to agree with pretty much everything you say BUT in terms of
expense and availability I would look at my motor with the idea that unless
I were replacing the whole thing I would opt for a pitch change before I
would get hung up on getting a motor that may not be obtainable at the
moment. Your points are very well taken though and if you can find the gear
ratio option it is an easy cure for the thrust question.


There are no easy cures. Changing the pitch to overcome a design
deficiency
is asking for trouble down the line.


Best;
Chris

"Sherwin Dubren" wrote in message
...

Hi Chris,
Your point about the 4-strokes developing power (or torque) at lower
rpm's
than 2-strokes is correct, but I'm not sure that leaves the gear ratio's
out
of the picture entirely. First of all, why would Yamaha and Mercury go
to higher
gear ratio's on their 'high thrust' engines, if it would be simpler to
just change
the propellor pitch to achieve the same result? Secondly, I would be a
little
nervous about experimenting with a propellor's pitch to match it
optimally to
the engine. The bottom line is will a 4-stroke engine with a low gear
ratio
and a compensating pitch propellor run as well as a 4-stroke with a
higher
gear ratio engine with it's appropriate propellor (I don't think so).
Actually,
both the higher gear ratio and the propellor can each contribute to the
higher
thrust. However, given a choice, I would go with the higher gear ratio
which
would allow me to get even more thrust by decreasing the propellor
pitch. With
the lower gear ratio engines, I can only lower the pitch of the
propellor which
has obvious limits as to how much this can be done.

Sherwin Dubren

Chris Edmonson wrote:

All good points being made here. If the wieght maximum you have in mind

is

clear to you then go with a smaller four stroke. I have found it

difficult

to move much more than fifty or sixty pounds of bulky motor around so

would

tend to go with a smaller motor than a lot of folks might choose. The

other

thing is that the four strokes make power at a lower RPM so may be best

on

fuel economy over the long run. The gear ratio is perhaps not as large

an

issue as it was when almost all of the motors were two strokes that

needed

the higher RPM's to get you going. The propeller's pitch can give you

some

of the pushing power that the old gear ratio change would give. If you
don't have enough umph move down a couple of inches in pitch and gain

power

earlier in the curve. The four strokes definitely handle this change

very

well.

Best;
Chris

"Bruce" wrote in message
...

I need to buy an outboard for my San Juan 21 and not quite sure about

how

big to go. I would like a 4 stroke and I am thinking that about 5 HP

would

be a good size. Any comments about the different brands would be
appreciated.
Also, do I really need a "long shaft" motor. With the motor mount

currently

on the boat, it seems to me that any motor would easily bury the prop.

Regards,
Bruce

Outboard recommendations for a San Juan 21
 

Sherwin;

Generally I have not gone to the edge of the rpm range to move the boat in
wind or current. However, I have to add that I sail when at all possible so
do not rely on the motor as much as some might. My most usual time to turn
the motor on is when I leave the dock until I get out just far enough not to
pose a danger to other traffic. From an anchorage I will set the sail
instead of motor off... to me motors are just a noisy niusance. There isn't
much current close in the harbor or near the coves I use most so it's not an
issue. At those times when it is I still prefer to sail out.

Best;
Chris

"Sherwin Dubren" wrote in message
...
Chris,

You mention that you could always get your boat up to hull speed
before
you hit maximum throttle rpm's. Now, was that in calm waters or going
downwind. I think you will find trying to make headway into a strong
wind and sea puts more demand on the engine. It's for those unusual
conditions that I would be willing to put up the extra cash to get the
reserve power. My only regret is that they have not come up with a
four stroke engine with a reasonable weight. I could heist my 65 pound
Chrysler Sailor over the transom into the boat, at sea. I cannot do
that
with my 4 stroke 99 pound Yamaha. I would have gotten a 2 stroke but I
am tired of mixing the oil with the gas, the loud noises from the
engine,
plus the worry that the government is going to put some kind of
restrictions on 2 stroke engines.
There are places to economize in boating, but for anyone doing
serious cruising (not day sailing), the added expense of a strong engine
is worth it. As I mentioned before, the higher gear ratio gives you
more leeway to increase your thrust, beyond what changing the propellor
can do.
It's true that high gear ratio engines are getting harder to find,
but not impossible.
Two years ago, while on a vacation to the Florida Keys, I found that my
Chrysler had
frozen up in storage beyond repair. I had to hustle to get a Yamaha
dealer to truck
one down from Miami since there were none available locally. I'm sure
that if people
are not pressed for time like me, they can order any engine they want.
If people were
more knowlegable about sailboat engines, they would not get stuck with
these motor boat
engines, and wouldn't have to change props as an afterthought.

Sherwin

Chris Edmonson wrote:

Sherwin;

True enough that gear ratio is of import but I think in the dollar range
I
have seen people willing to spend a $150 propeller change will get more
for
the expense than the $700 to $1500 sometimes charged for gear change.
The
retail marine motor business is spotty at best. Often someone looking
for a
particular motor will find that particular motor difficult to obtain. I
have even had people look into changing a short shaft motor into a long
shaft motor along with a gear change... just not cost effective. I
guess I
was thinking more of someone wanting to correct a situation with an
existing
motor than getting a new one.

Motors are set up for the different kinds of jobs they do. A work boat
will
typically have the "high thrust" version whereas a sport fishing boat
often
goes for speed / troll trade-offs. A sailboat that cannot plane does
not
need a high pitch prop (equates to higher end speed in a planing hull).

Assuming that their gear ratio will allow them to get enough thrust
with
more conventional pitch props.

The
rule of thumb is that for every inch of pitch change you will increase
or
decrease your max rpm's by 150 tp 200 rpm (a fact that is written on the
Mercury propeller box). For fuel economy you might choose a lower pitch
that will make power at a lower rpm... in a way this IS a gear change.
On
my own sailboats I have gotten hull speed long before I ever get to max
thrust of the motor. It has allowed a smaller motor to be used and
saved on
the expense and wieght of the larger motor and the fuel savings on a
long
use of the motor. This last is relatively unimportant because in a
season's
use I can count the tanks used on one hand!

Because the high thrust option is needed to extend even further the
range of
useful power generated by the engine it is reasonable to make a motor
with a
MUCH higher gear ratio... so in terms of designing a workboat or
sailboat
motor it is understandable that the gear ratios are offered. It is just
that they are not readily available everywhere. There are charts at
almost
all marine motor dealers that match pitch to a variety of motors so
there
isn't really much experimenting to do to get the power you are seeking.
Overall I have to agree with pretty much everything you say BUT in terms
of
expense and availability I would look at my motor with the idea that
unless
I were replacing the whole thing I would opt for a pitch change before I
would get hung up on getting a motor that may not be obtainable at the
moment. Your points are very well taken though and if you can find the
gear
ratio option it is an easy cure for the thrust question.

There are no easy cures. Changing the pitch to overcome a design
deficiency
is asking for trouble down the line.


Best;
Chris

"Sherwin Dubren" wrote in message
...
Hi Chris,
Your point about the 4-strokes developing power (or torque) at
lower
rpm's
than 2-strokes is correct, but I'm not sure that leaves the gear
ratio's
out
of the picture entirely. First of all, why would Yamaha and Mercury
go
to higher
gear ratio's on their 'high thrust' engines, if it would be simpler to
just change
the propellor pitch to achieve the same result? Secondly, I would be
a
little
nervous about experimenting with a propellor's pitch to match it
optimally to
the engine. The bottom line is will a 4-stroke engine with a low gear
ratio
and a compensating pitch propellor run as well as a 4-stroke with a
higher
gear ratio engine with it's appropriate propellor (I don't think so).
Actually,
both the higher gear ratio and the propellor can each contribute to
the
higher
thrust. However, given a choice, I would go with the higher gear
ratio
which
would allow me to get even more thrust by decreasing the propellor
pitch. With
the lower gear ratio engines, I can only lower the pitch of the
propellor which
has obvious limits as to how much this can be done.

Sherwin Dubren

Chris Edmonson wrote:

All good points being made here. If the wieght maximum you have in
mind
is
clear to you then go with a smaller four stroke. I have found it
difficult
to move much more than fifty or sixty pounds of bulky motor around
so
would
tend to go with a smaller motor than a lot of folks might choose.
The
other
thing is that the four strokes make power at a lower RPM so may be
best
on
fuel economy over the long run. The gear ratio is perhaps not as
large
an
issue as it was when almost all of the motors were two strokes that
needed
the higher RPM's to get you going. The propeller's pitch can give
you
some
of the pushing power that the old gear ratio change would give. If
you
don't have enough umph move down a couple of inches in pitch and
gain
power
earlier in the curve. The four strokes definitely handle this
change
very
well.

Best;
Chris

"Bruce" wrote in message
...
I need to buy an outboard for my San Juan 21 and not quite sure
about
how
big to go. I would like a 4 stroke and I am thinking that about 5
HP
would
be a good size. Any comments about the different brands would be
appreciated.
Also, do I really need a "long shaft" motor. With the motor mount
currently
on the boat, it seems to me that any motor would easily bury the
prop.

Regards,
Bruce

Outboard recommendations for a San Juan 21
 

Steve;

My suggestion for this boat would be a 6 h.p. four stroke. Unless you have
long periods of motoring that dictate other reasons for more horsepower this
will likely give you hull speed for the 3,000 or so pounds of displacement.
Just my opinion though.

Best;
Chris

"Steve Zweigart" wrote in message
...
I, too, am in a quandry about replacing the 1989 Mariner 9.9 kicker on
my Mac25. I've named the engine "Sybil" due to its several
personalities, one of which involves dying in order to test my
seamanship at the most intersting moments imaginable.

Anyway, I'm interested in a 4-cycle for quiet operation, and I want the
smallest, lightest engine that will push my boat at its hull speed of
6.7mph reliably and safely under varied conditions. You would think
that there would be some scientific way to figure this out, but nobody
seems to know for sure.

SZ


Sherwin Dubren wrote:
Chris,

You mention that you could always get your boat up to hull speed
before
you hit maximum throttle rpm's. Now, was that in calm waters or going
downwind. I think you will find trying to make headway into a strong
wind and sea puts more demand on the engine. It's for those unusual
conditions that I would be willing to put up the extra cash to get the
reserve power. My only regret is that they have not come up with a
four stroke engine with a reasonable weight. I could heist my 65 pound
Chrysler Sailor over the transom into the boat, at sea. I cannot do
that
with my 4 stroke 99 pound Yamaha. I would have gotten a 2 stroke but I
am tired of mixing the oil with the gas, the loud noises from the
engine,
plus the worry that the government is going to put some kind of
restrictions on 2 stroke engines.
There are places to economize in boating, but for anyone doing
serious cruising (not day sailing), the added expense of a strong engine
is worth it. As I mentioned before, the higher gear ratio gives you
more leeway to increase your thrust, beyond what changing the propellor
can do.
It's true that high gear ratio engines are getting harder to find,
but not impossible.
Two years ago, while on a vacation to the Florida Keys, I found that my
Chrysler had
frozen up in storage beyond repair. I had to hustle to get a Yamaha
dealer to truck
one down from Miami since there were none available locally. I'm sure
that if people
are not pressed for time like me, they can order any engine they want.
If people were
more knowlegable about sailboat engines, they would not get stuck with
these motor boat
engines, and wouldn't have to change props as an afterthought.

Sherwin

Chris Edmonson wrote:

Sherwin;

True enough that gear ratio is of import but I think in the dollar range
I
have seen people willing to spend a $150 propeller change will get more
for
the expense than the $700 to $1500 sometimes charged for gear change.
The
retail marine motor business is spotty at best. Often someone looking
for a
particular motor will find that particular motor difficult to obtain. I
have even had people look into changing a short shaft motor into a long
shaft motor along with a gear change... just not cost effective. I
guess I
was thinking more of someone wanting to correct a situation with an
existing
motor than getting a new one.

Motors are set up for the different kinds of jobs they do. A work boat
will
typically have the "high thrust" version whereas a sport fishing boat
often
goes for speed / troll trade-offs. A sailboat that cannot plane does
not
need a high pitch prop (equates to higher end speed in a planing hull).


Assuming that their gear ratio will allow them to get enough thrust
with
more conventional pitch props.

The

rule of thumb is that for every inch of pitch change you will increase
or
decrease your max rpm's by 150 tp 200 rpm (a fact that is written on the
Mercury propeller box). For fuel economy you might choose a lower pitch
that will make power at a lower rpm... in a way this IS a gear change.
On
my own sailboats I have gotten hull speed long before I ever get to max
thrust of the motor. It has allowed a smaller motor to be used and
saved on
the expense and wieght of the larger motor and the fuel savings on a
long
use of the motor. This last is relatively unimportant because in a
season's
use I can count the tanks used on one hand!

Because the high thrust option is needed to extend even further the
range of
useful power generated by the engine it is reasonable to make a motor
with a
MUCH higher gear ratio... so in terms of designing a workboat or
sailboat
motor it is understandable that the gear ratios are offered. It is just
that they are not readily available everywhere. There are charts at
almost
all marine motor dealers that match pitch to a variety of motors so
there
isn't really much experimenting to do to get the power you are seeking.
Overall I have to agree with pretty much everything you say BUT in terms
of
expense and availability I would look at my motor with the idea that
unless
I were replacing the whole thing I would opt for a pitch change before I
would get hung up on getting a motor that may not be obtainable at the
moment. Your points are very well taken though and if you can find the
gear
ratio option it is an easy cure for the thrust question.


There are no easy cures. Changing the pitch to overcome a design
deficiency
is asking for trouble down the line.


Best;
Chris

"Sherwin Dubren" wrote in message
...

Hi Chris,
Your point about the 4-strokes developing power (or torque) at lower
rpm's
than 2-strokes is correct, but I'm not sure that leaves the gear
ratio's
out
of the picture entirely. First of all, why would Yamaha and Mercury go
to higher
gear ratio's on their 'high thrust' engines, if it would be simpler to
just change
the propellor pitch to achieve the same result? Secondly, I would be a
little
nervous about experimenting with a propellor's pitch to match it
optimally to
the engine. The bottom line is will a 4-stroke engine with a low gear
ratio
and a compensating pitch propellor run as well as a 4-stroke with a
higher
gear ratio engine with it's appropriate propellor (I don't think so).
Actually,
both the higher gear ratio and the propellor can each contribute to the
higher
thrust. However, given a choice, I would go with the higher gear ratio
which
would allow me to get even more thrust by decreasing the propellor
pitch. With
the lower gear ratio engines, I can only lower the pitch of the
propellor which
has obvious limits as to how much this can be done.

Sherwin Dubren

Chris Edmonson wrote:

All good points being made here. If the wieght maximum you have in
mind

is

clear to you then go with a smaller four stroke. I have found it

difficult

to move much more than fifty or sixty pounds of bulky motor around so

would

tend to go with a smaller motor than a lot of folks might choose. The

other

thing is that the four strokes make power at a lower RPM so may be
best

on

fuel economy over the long run. The gear ratio is perhaps not as
large

an

issue as it was when almost all of the motors were two strokes that

needed

the higher RPM's to get you going. The propeller's pitch can give you

some

of the pushing power that the old gear ratio change would give. If
you
don't have enough umph move down a couple of inches in pitch and gain

power

earlier in the curve. The four strokes definitely handle this change

very

well.

Best;
Chris

"Bruce" wrote in message
...

I need to buy an outboard for my San Juan 21 and not quite sure about

how

big to go. I would like a 4 stroke and I am thinking that about 5 HP

would

be a good size. Any comments about the different brands would be
appreciated.
Also, do I really need a "long shaft" motor. With the motor mount

currently

on the boat, it seems to me that any motor would easily bury the
prop.

Regards,
Bruce