Would You Ever Repower a 22' With a 60 Horse Outboard ?

A

Adeline

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The price of gas is skyrocketing and I'm thinking of different options for repowering Adeline's 18 year old Johnson 70. I see that Yamaha's 60 weighs only 237#s. That's 122#s less than their 75/90. Gear ratio is 1.85:1 -vs- 2.31:1. Displacement is 996 ccs -vs- 1596 ccs. Since I don't care about speed as much as fuel economy, is this a motor worth considering or is it simply too small ?
 
Adeline":5aj7rtyc said:
The price of gas is skyrocketing and I'm thinking of different options for repowering Adeline's 18 year old Johnson 70. I see that Yamaha's 60 weighs only 237#s. That's 122#s less than their 75/90. Gear ratio is 1.85:1 -vs- 2.31:1. Displacement is 996 ccs -vs- 1596 ccs. Since I don't care about speed as much as fuel economy, is this a motor worth considering or is it simply too small ?
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Hi Pete,

It won't make any practical difference until you exceed perhaps 80% power on the smaller engine or choose to travel faster with the larger engine. If you want to run at 12 knots the 60 will be doing about all it can (for a continuous cruise rpm) while the 75/90 will be in its mid range. From there and below it won't make much difference. If you want to cruise at 14 or 15 knots the 60 would be screaming and the 75/90 doing much better. So it really becomes a matter of speed desired; the F75 at 6 knots will not burn any more fuel than the F60 at 6 knots; they both have to make the same horsepower (there is a weight difference but at that speed it isn't an issue).

Also remember that with the larger engine you do have the option of running faster if you need to and you have more power to deal with rough conditions (like hanging on the backside of a wave in a following sea and really needing something to happen NOW). The only downsides to the larger engine are initial expense and using more fuel if YOU don't regulate the throttle and keep the speed down. Your resale will be much higher on the larger engine as well; few C-Dory buyers would be happy with the F60 (not all mind you; they'd just be fewer and further between).

I can do a lot more numbers for you but the pertinent question is how fast do you want to cruise?
 
Pete-

According to a sales brochure I have, the Yamaha 75 and 90 actually weigh 369 lbs, even more than your figures.

The boat with a light 60 hp engine would plane easier, but might be marginal or underpowered if you carry a lot of weight in terms of equipment or passengers.

We do know that a 50 hp motor won't plane the boat when one of a pair conks out, and I think this means that the 60 would be pretty marginal, even w/o the extra engine weight.

For a little more margin, you might also look at the Suzuki 70, wich has 1298 cc and weighs 335 lbs.

I think the smaller lighter engines will give you better gas mileage with their lighter weight, but that to go say, 15 mph, you need so much power and eiher engine will use much the same amount of gas to develop it.

Another factor might be that the smaller engines will wear out quicker than a larger one that isn't being taxed so heavily working at a lower rpm/throttle setting.

You might look at a light weight Evinrude etec to get both the light weight and have reserve power at the same time.

Just some thoughts...

Joe. :teeth
 
Pete,

I'm considering doing the same thing and for the same reasons. I think the Yamaha T60 High Thrust is ideal for the fisherman with a C-Dory.

I've already started the planning stage, after I took my 91 Yamaha 90 off off the boat and gave it to my brother-in-law. I'll keep my 9.9 Yamaha high thrust for trolling. I'm going to lighten up the transom by pulling out the two 18 gal tanks and replacing them with 12 gal tanks. If I can find a place for the battery, it's going forward.

At $4 a gal., I think it will be around for quite a while and it's not going to interfere with fishing. And, I plan to stay close to home as the price of diesel fuel is killing me.

Bill
 
Unless you only want to cruise at 10 to 12 knots, and even with the low planing speed of the C Dory 22, that will be hard on the smaller engine.

Unless you are staying at displacement speeds--less than 5 knots, you will get better mileage with the boat on a plane at 15 knots. The larger engine will work less, and last longer--and may well get better gas mileage. We talk about HP, but it is also about torque. The larger engine will have more torque, and get the boat on a plane faster.

I also see that small engine as being a potential safety issue. If you have to run fast to beat weather or get thru a pass where there is a lot of current, there will not be that extra reserve.

I agree the light weight E tec might give you the best service. But, there have been problems in the past with plugs fouling at low speeds--so if that is still the case, it would be counter productive.
 
Quite a few year back now, Trailer Boats Magazine did a test on outboard horsepower fuel useage.

The point was that using the same boat but changing engines showed that more horsepower did not consume more fuel unless you used more horsepower.

They used 3 Mercury Outboards of different horsepower and it showed that to do say 25 mph all of the engines burned very very close to the same amount of fuel.

We have found that trucks are the same, if you use 150 hp, whether the engine had a 200 hp engine or a 340 hp engine, the fuel useage will be about the same.

Some things to consider is that with fuel injection the fuel usage will be very close to propel a boat the same speed regardless of engine size.

With a bigger engine there is always the temptation to use the horsepower.

Rick
 
As far as my answer to the subject line of this thread - simply NO. In addition to the reasons stated above by Bob, the resale value of a boat equipped as described will be low because no-one else wants such an under powered CD 22. The typical twin 40s or single 90 are typical for a reason.
 
there is a older cdory 22 in the water in everett with a single 40hp. The only time I have seen it out it was doing 6knots or so. I doubt that motor will plane that boat. this last weekend it was out of the water getting the bottom cleaned. I doubt a act of god could have planed that boat with all the crud that was on it. I am trying to find out who the owner is. This boat needs a lot of work and may be for sale soon from what the marina crew said.
 
Hi Pete, I power Raven Dancer with a 75 HP Yamaha and can't complain about the MPG. I think when I come to upgrade time I will get the 90 Yamaha, just to have the extra power if needed.
If I want to save fuel I just drop the 8 HP kicker down and run along at 5 knots, for some unknown reason that little 8 HP does not burn any fuel ! :lol: I have it tapped into the main tank and have trolled around all day long on maybe a couple of gallons of gas and a few drops of 2 cycle oil. :D
By the way Ruthi and I are enjoying the little dingy we bought from you, thanks again. :lol:
Big Dave.
Raven Dancer.
 
A person could actually get worse gas milage with the smaller motor if it has to run at a higher RPM to do the same job. Probably wouldn't if used in the manner described above but I would never consider buying 22 with anything less than a single 90. Sometimes I wish I had more power for my off shore fishing trips.
 
I don't have good figures for MPG or GPH but we figure roughly a dollar per mile, and 4-5 MPG. But with the twin 40's, if we want to just put along at 4-5 knots, I shut one down and raise it. Goes great and if we are in the shallows, one engine is protected. Don't think I would want to have less than the 80 horse power on a moderately loaded 22.
Harvey
SleepyC :moon

edit x 1 for spelling
 
I'm looking at a Trailer Boats magazine dated October 1990. The article is about a 22 ft. C-Dory Angler powered by a 200# Yanmar Diesel outboard rated at 27 hp. A quote from the article, "The Yanmar diesel outboard was a pleasure. As expected, speeds are not blazing, but I recorded a solid 15 mph and we were comfortably on a full plane with four people onboard."

Another quote from the same article, "The hull design of the C-Dory is ideally suited to take advantage of an engine with modest horsepower, and the fuel economy should be outstanding."

Bill
 
The problem is that the diesel outboards will not meet the air polution standards. Thus it is not available in the lower 48. One of my Canadian friends had tried to find one in Canada and was unsuccessful.

Occasionally these diesels come up on E bay--and they must be grandfathered in. Penta used to make a multi fuel engine--and Evinrude has made a multifuel 55 hp (mainly to run on JP-4, JP-5, JP-8, Jet-A and Jet-B, kerosene, standard gasoline and, in an emergency, diesel fuels.) outboard for the military.


But for us normal souls these engines do not seem to be available.
 
a different comparison, years back a friend pulled a 351 Ford out and installed a 460 GMC (also larger prop) his gas dropped from just under 15 gals to under 10 gals per hour with the 460 (now a dinasour) .... depends on your travels but under powered usualy cost more in fuel ... wc
 
I might look at a C22 with an 80 hp Yamaha. Does anyone have one like this? What can I expect with a medium load vs. a 90hp?. And, if it has digital gauges, can I get an hour readout? The owner doesn't seem to know. Thanks.

Harry
 
Honda did prop tests on various 22 Cruisers over the years. I've posted a link to these tests before. Here's a link to their prop test main page.
http://www.honda-marine.com/performancetest.aspx#331

Here's a link for a BF50.
http://www.honda-marine.com/pdfs/ptC%20DORY%205.pdf

Here's a link for a BF75.
http://www.honda-marine.com/pdfs/ptC%20DORY%201.pdf

Here's a link for a BF90.
http://www.honda-marine.com/pdfs/ptC%20DORY%204.pdf

I suspect a 60 would be somewhere between the 50 and the 75, but that's a pretty wide range. The difference between the 75 and the 90 doesn't seem so great.

Have fun!

Mike
 
Harryr,
I have a 115 Yahama 4 stroke 2003 engine on a different boat than a C Dory. The digital guages show the engine hours on that engine.

I think that the 80 on a C Dory would perform up to the boats' performance. These boats are not meant to be fast boats (I found that on my 22 anything over 30 MPH was a little skiddish)--and I would expect that in a medium load with the correct prop you would hit the high 20's to 30 mph. Yahama engines have a good reputation.
 
As previously said, I think you would be sacrificing safety, fuel mileage, and resale value by going that small. I repowered with a 90 Suzuki a couple years ago and have discovered the joys of displacement cruising; I literally enjoy myself more and get great fuel mileage which allows me on a limited budget to stay very active in boating. I also run pretty heavy so I feel the need for the extra power.

I have many friends who are trying to sell their boats or who just keep their boats idle due to the fuel costs, thankfully, we have boats that still allow us to enjoy being on the water.

Yamaha, Suzuki, Honda and Evinrude all make very good motors. I dont include E-Tec only because of some cold weather issues up here but we are lucky to have such reliable motors. I had a Mariner once about 20 years ago when I lived in NC and have to say I was not so blessed.
 
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