Outboard Size??

Discussions about Cape Dory, Intrepid and Robinhood sailboats and how we use them. Got questions? Have answers? Provide them here.

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hwh888
Posts: 23
Joined: Jun 25th, '09, 13:54
Location: CD22 Searcher Hull #8 Caribbean - West Indies

Outboard Size??

Post by hwh888 »


I have a CD22 with a 6 hp outboard which is old & tired.
I have a chance to buy a 4hp new but not sure if that smaller engine is strong enough to push this CD22.
Anyone have experience using a 4hp ??
Many Thanks,
Harry
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bhartley
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Joined: Aug 23rd, '05, 09:26
Location: Sea Sprite #527 "Ariel"
CD25D #184 "Pyxis"

CDSOA Member #785

Outboard

Post by bhartley »

We use a 3.5 HP Tohatsu 2-Stroke on our SS23 and it is more than satisfactory. They should be about comparable. We don't do a great deal of motoring. It is primarily there for maneuvering in harbors we visit and when the wind dies. In a blow, we reef and sail home.

We used to use a Johnson 6HP. Never got much past idle. Don't miss it at all.
shavdog
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Joined: Sep 5th, '07, 16:20
Location: None Right Now

4hp 1976 evinrude

Post by shavdog »

I have this motor on my 22 because it weighs only 38 pounds...problem is its old, no neutral, and so so on power into a wind...i think the two strokes have more power hp for hp but not certain...i'd probably go for a newer 4 stroke 6hp in the 55-60 pound range..
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Bill Moore
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Location: CD 22, Wind Song
Portland, ME

RE: Outboard size

Post by Bill Moore »

I have a 1996 4 HP long shaft two stroke Mercury. Just above idle will drive the boat at 4 knots. Give it a little gas and you can make hull speed. Be sure you get the long shaft. The only problem is rough weather when the prop comes out of the water.
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hwh888
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Location: CD22 Searcher Hull #8 Caribbean - West Indies

4 HP Feedback

Post by hwh888 »

Many thanks sailors for that information. Looks like I'll hang a 4hp off the stern.
Many Thanks,
Harry
rtwhitman2
Posts: 42
Joined: Nov 18th, '09, 12:06

outboards

Post by rtwhitman2 »

What mileage/runtime per gallon can one expect with a 4-6 HP outboard driving a smaller boat like a CD Ty? Assume calm seas.
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Bill Moore
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Joined: Feb 9th, '06, 13:08
Location: CD 22, Wind Song
Portland, ME

Your mileage may vary...

Post by Bill Moore »

I did a slapdash experiment on my CD22 and came up with 5+ hours per gallon for my 4 HP two stroke at just above idle (which in calm seas translates to about 4 knots). I don't usually show that kind of patience and run it a little faster, so I use 4 hours / gallon for planning plus a 0.5 gallon reserve. I do not have the standard prop and I don't know the pitch--it is what my outboard guy told me I needed.
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Duncan
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Montreal, QC

Outboard Fuel Consumption

Post by Duncan »

rtwhitman2 wrote:What mileage/runtime per gallon can one expect with a 4-6 HP outboard...
One rule of thumb is to divide the horsepower used by 10, to get fuel consumption in gallons per hour.

Thus, a 4 hp running at full throttle burns about 0.4 gallons per hour.
Bill Moore wrote:I did a slapdash experiment on my CD22 and came up with 5+ hours per gallon for my 4 HP two stroke at just above idle (which in calm seas translates to about 4 knots). I don't usually show that kind of patience and run it a little faster, so I use 4 hours / gallon for planning plus a 0.5 gallon reserve. I do not have the standard prop and I don't know the pitch--it is what my outboard guy told me I needed.
Using the rule of thumb above, but backwards, that implies that you are running your engine at about 2.5 hp, or about 60% of its nominal rating.
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Gary M
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1982 CD22
Marina del Rey, CA

1/3 gallon per hour

Post by Gary M »

I can count on burning 1/3rd of a gallon per hour on my CD22 with a 5 HP Nissan 2 stroke outboard.

One 3 gallon tank of gas would last a year if I didn't take any longer trips or go for harbor cruises under power.

I have a second 3 gallon tank I take along if there is any doubt at all that one tank may not be enough.

BTW, this outboard does a fine job for me, but I would not hesitate going a little smaller.

Gary
Oswego John
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GPH

Post by Oswego John »

Gary M wrote:I can count on burning 1/3rd of a gallon per hour on my CD22 with a 5 HP Nissan 2 stroke outboard.

One 3 gallon tank of gas would last a year if I didn't take any longer trips or go for harbor cruises under power.

I have a second 3 gallon tank I take along if there is any doubt at all that one tank may not be enough.

BTW, this outboard does a fine job for me, but I would not hesitate going a little smaller.

Gary
I have to go along with just about what Gary said. I have a 5 HP 4 stroke Mercury on my Ty W/E. I use the motor mostly to get away from my finger pier and to get the sails up in open water. A 3 gal. can lasts the season.

A smaller motor would do the job but I bought a 5 HP because when I bought it, it was the only motor that had F-N-R, and I needed reverse.

As it worked out, I run the motor less than 1/2 throttle. Once in a while I open the motor up to blow her out. The 5 HP comes in handy when I am in the river and the extra power helps when the current is high.

I have had zero problems with my engine and it has proven very dependable. I forget its weight, probably somewhere near 50+ pounds but I leave it on all the time.

All the best,
O J
"If I rest, I rust"
Voting Member #490
rtwhitman2
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Joined: Nov 18th, '09, 12:06

More outboard Qs

Post by rtwhitman2 »

I gather from the feedback that a 5 gal tank could take one up to 100 miles, plus or minus. I'm also curious about the drag of an outboard situated in an engine well (CD 22s and 25s) while under sail. The engine well solves the problem of hiding/storing the engine, but will an engine run in a well with the well hatch closed? I seem to remember being on a CD 25 where the hatch had to be open for the engine to run. I think with it closed the engine was not getting enough oxygen. I also came accross information on a CD 22D which had a small inboard diesel. I think they only made 57 of the CD 22s so the D version must be fairly rare. I've been looking at Tys, and now 22s, with an eye toward getting a boat that I can cruise on for a week or so.
Adamhagan
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Location: 1979 CD30k Eleventh Hour--New York City, NY

CD25 4-stroke vs 2-stroke, mileage and comparison

Post by Adamhagan »

"I gather from the feedback that a 5 gal tank could take one up to 100 miles" As long as you have oars on board.

I recently delivered my CD25 from the Potomac river, MD to Oriental, NC and can offer some perspective on the topic. No expertise is expressed or implied.

I started out with a 1997 Yamaha long shaft 6HP 2-stroke, it was serviced (water pump, impeller, lower unit, etc..) before the trip. With 2 3-gallon tanks I would achieve around 50 miles tops. I was on a deadline (never good when sailing) after hurricane Irene ate all my extra days.

100 miles from my destination the carb got clogged, and I knew someone selling a 2010 Nissan 6hp 4-stroke for a real deal. I finished delivery with the new engine and have since fixed the old Yamaha.

MY 2-cents:
-The 4 Stroke uses less than HALF the fuel.
-A mere human like me can rebuild a 2-stroke carb (good).
-2-strokes are MUCH more subject to bad fuel and debris once you add oil (bad).
-I can achieve hull speed with both but with the 4-stroke I will still have some residual hearing at days end.
-The lazarette hatch can be closed with the 4-stroke not with a 2-stroke.

Shavedog said the 2-stroke has more power: for me the newer 4-stroke outperformed in power based on COG. Now responsivness getting a dinghy on a plane would make a difference.

For a 25 nothing smaller than a 6hp as I found out entering the Norfolk inlet against tide after a hurricane storm surge...motorsailing next to a naval destroyer hoping not to get run over.
Kind Regards,

Adam
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Jim Davis
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Edgewater, MD

Good analysis

Post by Jim Davis »

However you need to be careful with is Ethenol. It can really screw up a four stroke. I have put a small Favor (Honda label ) in the fuel line. This is primarily to trap any water. I also use StaBil and try to refuel at least once a month. If at home I put the old gas in the car. Many trips to the mechanics taught me that, also the cost involved. A four stroke is too sensative to fuel
Jim Davis
S/V Isa Lei
Kilgore
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Sea Cliff, NY
Member #1209

Re: Good analysis

Post by Kilgore »

Jim Davis wrote:However you need to be careful with is Ethenol. It can really screw up a four stroke. I have put a small Favor (Honda label ) in the fuel line. This is primarily to trap any water. I also use StaBil and try to refuel at least once a month. If at home I put the old gas in the car. Many trips to the mechanics taught me that, also the cost involved. A four stroke is too sensative to fuel
Agree. My Tohatsu 6 idles like a$$ with pump E10. Switched back to marine valvtec and it's much improved.
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Jim Davis
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Spelling correction

Post by Jim Davis »

Favor should be Racor filter. My Droid spell check got me.
Jim Davis
S/V Isa Lei
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