Honestly how many ponies do you prefer on a 25'

B

bshillam

Member
I have seen 135-200 on the CD 25. I have also read a few post on this site about HP ratings and motors on the 25. I'd like to hear first hand, what HP rating do you have and would you prefer something different? Also what kind of economy you receive from your outboard set up? Thanks much!
 
bshillam":3kubaluw said:
I have seen 135-200 on the CD 25. I have also read a few post on this site about HP ratings and motors on the 25. I'd like to hear first hand, what HP rating do you have and would you prefer something different? Also what kind of economy you receive from your outboard set up? Thanks much!
Click to expand...

I bought a 175 Suzuki for my "03" 25, had there been a 200 suzi or Yamaha available that is what would be on it. I can cruise @ 4500 rpm, 17p prop, 18 knots & 10 gph, full fuel & water (8,000# ish). Light load, flat water, 19p prop, 6200 rpm = 35 knots @ 27gph :shock: :mrgreen: :mrgreen: (the boat handles just fine at that speed despite all the B/S you read here!) :monty

Have a good one!!
 
Ours had twin 90s and while that was fine with 2-2.5mpg consumption and 30knot+ top speeds and great for maneuvering, I would have rather had a single 175-200 on the back. Less weight and simpler rigging plus a simple kicker.

Greg
 
Many of the earlier boats had 130's which was the souped up 115, and those were under powered. That is what we had, it the boat needed more. I would say at least 150 (although the 135 Honda is the same block, and the only difference is the valve timing at the top end. I also like the 150/175 Hondas, and think that is one of the best combo's of that boat. I cannot comment of the handling over 30 mph on the 25, because with the 130 you could not reach that speed.

As for two 90/s vs one 150, there is a big weight difference (720# for two 90's, and 485 for a single 150. Add a 110# kicker, and you are still over 120 lbs heavier for the dual 90's. The boats are stern heavy to start with.
 
I got Journey On up to 25 knts. It wasn't the handling I remember, it was the pounding over the ripples. All C-Dorys have a fairly flat bottom and they don't do real well on slicing through the waves.

So, to anybody who gets 35 knts out of a 25 has my compliments. I hope the water was like glass.

I've been underpowered my whole life.

Boris
 
I recently did some speed testing. On almost flat water with little or no current, I got 32 MPH (not knots) at 5600 RPM with a S3x14.5x15R SS prop and and Honda 150 on a CD25 loaded relatively heavy and just me on board.
 
We have a Suzuki 150DF and it has always done what we needed it to do. I am a type A when it comes to maintenance. We rarely "floor it". Most of our trips are between 3500 and 4500 rpm's. I have had it maxed out with a light load & flat water and she topped out at ~29 knots.

IIIRC Marc at Wefings recommended the Suzuki 175; best of both worlds. Weight of a 150 but more power.
 
I have had the good fortune to drive a lot of boats with a lot of motors and i have always thought the 135 hp to 150 were under powered to my taste. a 175 to 200 is more in line with what should be on the boat.

I have always thought that driving a boat at 25 mph at half or 3/4 throttle was a better idea then driving a boat at 25 mph at full throttle. Better fuel mileage at lower rpms.

I have a 225 on my 27. (bit of a different cdory then the 25) and rarely run at more then 4000rpm ( 25 mph with a heavy boat). I can get up to 35 plus on clean water but have no need to. While fishing the other day we ran back from the bar with 4 on board in heavy chop at 27mph at 4300rpm with the bow down. One of the advantages of having more motor is lowering your bow into the chop and smoothing out your ride with out losing speed. You just burn a little more gas.
 
While we have a 150 on Daydream, I sort of have to agree with Tom...run a bigger engine at a lower throttle setting for better overall efficiency. Plus you have the oomph to get 'er really going if the going gets tough.
 
No argument against a larger engine running at a lower RPM, but does that really provide better fuel "mileage"? I thought I had read (here in the past) that basically it takes "X" power to run the boat at "X" speed and strictly for fuel efficiency it doesn't take measurably more or less fuel to be running, say, a 200hp at one level or a 150hp at another level.

(Obviously not talking about extreme outlier engine sizes.)

Is this not generally true then?
 
Larger motors running at a lower RPM (larger prop) to push the same boat the same speed as a smaller motor spinning faster can use less fuel. Brands and models vary based on fueling design and parameters. Talking with an honest professional can reveal some recommendations that are counter intuitive. I clearly remember being surprised by the advice of one of our local experts when it came to re-powering.

Greg

One example graph of two motors on the same boat.

http://s177.photobucket.com/user/Whaler ... 2.jpg.html
 
That graph that Greg posted is very interesting. When we were in the buying process for the 25, Jeff M. asked how we intended to use our boat. Our response: "Cruising - displacement speeds and mid to upper teens." He recommended the Honda 135. The Honda 135 and 150 are the same block, with the 150 gaining those extra horses above 4800 RPM.

My original thought was to put twin 90s on... at the time, though, the Honda 90s were not fuel injected. Having FI was important to us.

For our use, the 135 was a good solution. As a side note, most of our boating was done at sea level. The performance at high elevations (Lake Yellowstone: 7,800'; Jackson Lake: 6,800'; Lake Tahoe: 6,200') was a bit lacking (same could be said for the crew :wink: ), but a prop change could bring most of that back.

Each owner will have a different idea of the best combination of size/hp/weight/speed. This is a circumstance where "YMMV" is appropriate.

Good luck with the decisions,
Jim
 
If you look at the second graph (click right arrow) you see that the opposite is also true. Although it doesn't say what boat the graph represents but it is still comparing an Etec 150 to a 115. In the second graph you'll see that while the first graph shows that the 150 is more efficient at ~40mph than the 115, in the second graph the 115 is more efficient at ~25mph. The first graph also shows that the 115 is more efficient above ~48mph until the 115 runs out of steam.

Also, the graphs show that the max difference in efficiency (where the engines overlap) is about 1 gph max.

I guess, like a lot of things, the answer is "It depends."
 
One always has to know exactly (as much as possible) is involved in graphs such as posted above. There is a very lengthy discussion of the Boston Whaler site, which relates to these graphs:
http://continuouswave.com/ubb/Forum4/HTML/007588.html
Basically there are many variables, including boat design, temperature, altitude, water conditions, engine design, number of cylinders, weight of engines, props, weight of boat, gear ratio in lower units, etc. including errors in the instruments. So you cannot take two graphs as be representative of all cases.

For example how accurate are the fuel burns claimed on the C Brat site? Obviously some are more accurate than others, depending on how it is measured, amount of running time at each speed/RPM, boat loading, etc.

Generally one would favor the larger engines, up to a point. For me that point is giving adequate performance with the boat loaded as I run it (usually heavy), water conditions (often rough) and where (sea level and 3700 feet).
 
Chack Chack came rigged with Suzuki DF 140 which is a well loved engine, but as we progressed with our Great Loop trip it was apparent the boat was underpowered when heavy with supplies and people. We repowered with a Suzuki DF 200 which has been a great engine for the boat. The extra speed I think is useful if you are considering crossing fairly large bodies of water within a safe weather window, or will be running with cruising supplies and extra people.

The down side is the extra weight. Our 2006 CD 25 has a Honda 15 kicker, a Suzuki DF 200, water tank, 3 AGM batteries and the fuel tank all weighing down the stern. All that weight requires a lot of trim input to keep the bow down. We have improved on that by raising the DF 200 and using a powertech 4 blade prop.

Your might consider the new four cylinder Suzuki DF 200A that weights 498 pounds, 12% less than our V6 DF200 to help keep weight off the stern. As a bonus you can get it in white which would look great on a C Dory

I don't think you would regret the extra HP
Best
Eric
 
One thing to remember about the "new" 200A is that it is the same block as the 150; The same issue, with the Suzuki 140, being the same block as the 115. I suspect in both cases you will only get the advantage of the extra HP at high RPM. Suzuki is not the only company to do this…

You are getting an advantage of the increased displacement in that 6 cyl 200 hp engine--and a lot more torque.
 
Les from EQ has recommended the 115 Honda for the Marinaut even though it runs well with a 90. The relatively big heavy block (same as 135-150) and added torque being a benefit enabling lower RPM cruising and less "strain" resulting is lower fuel use, less noise, and longer engine life. So long as a hull can handle the weight, I would generally agree with that logic. As Bob says there are many variable but going big doesn't have to be about speed at all.

Our older twin 90s weighed right about 800 lbs together rigged on the boat. After I removed the rear holding tank, it was better balanced, but it would be pretty darn easy to get a 175-200hp unit plus a backup and still come in under that weight.

Greg
 
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