Hello,
I believe I have read the forum posts related to outboard options but wanted to see if there are people with real life experience with a 9.9 HP 4 stroke on a CP 23. If I get the correct mounting hardware, I am just wondering if there are any other drawbacks with the weight.
Thanks in advance,
Brian
In my opinion, yes. I have a 9.9 four stroke Suzuki electric start that came with my boat when I bought it. It is a great motor but in my opinion it is overkill with regard to power and is too heavy for the boat. It affects the trim. When I trailer I prefer taking the motor off and putting it in my truck bed (the mount mfg also says that is required but many don't do it) and the 9.9 at 104 lbs. is too heavy for one person to easily mount and dismount. The only way I can do it is to disconnect my truck from the trailer and back the bed under the motor and then with great difficulty I can lift it to the bed and set it down. Then reconnect the truck to the trailer. Adds about a half hour to the process each way. I'm currently trying to figure out how I'm going to get it off the boat at dock so I can winter service it. Going to take about three folks to do it safely.
I did a HP requirement for my 23 some time back and I think it came out to 5.6 HP. My Christmas present this year will be a 6 hp Tohatsu Sail pro. 59 lbs. The Suzuki will power a scallop/fishing skiff.
In my opinion, that motor is way, way too heavy to consider using.
-performance will be poor unless you counterbalance weight in the bow to the tune of 40lbs or more.
-Lifting the motor up after raising sail will be difficult at best.
-Mounting it will be a bear (100lbs of awkward weight)
-Mounting brackets and the board the motor clamps on may not be designed to carry the weight or prop torque
-Clearance between the aft rub rail and the motor might be tight (this is a guess based on how much larger the 9.9's motor case is than 8hp 2-strokes.
-More HP buys you zero add'l speed. A 6 hp motor will propel a 23 only a hair slower than a 9.9.
Hutchins recommends a 6-8hp two stroke (read: much lighter than 4 stroke equivalents) which typically weigh 55-65lbs. I wouldn't stray from this if you can.
Others will disagree with me and are using a 9.9 successfully, so take this as opinion rather than fact.
My CP23 came with a Nissan 9.9 HP 4 stroke electric start. I'm still young enough (29) that I can lift the motor on and off when trailering, but it is difficult. It does affect the trim and I carry an extra anchor up front and try to keep some water in my tank to offset some of the weight. It is definitely more power than needed. I would trade it for an 8 HP sailpro in a heartbeat.
What do I like about it? Very quiet (relative to a 2 stroke) and with 2 cylinders it doesn't vibrate much. It starts every time with no struggle (either by starter or manual). It sips fuel, got about 18 mpg at 5.5 mph on flat water for 8 hours (that's better than the truck I use to tow it).
Too much additional weight for really no gain. I went from an 8hp 2 stroke/2 cylinder to the 6HP SailPro. The Tohatsu drives the 23 just fine and weighs in at about 60 pounds. Being a single cylinder it vibrates a little more that the 2 cylinder but it is much quieter, idles in gear lower and gets far better fuel economy.
Shawn
Brackish,
Have a idea, it is what I do at work to get them off. First tie a line to it, long enough to do the following steps.
Put boat backed into slip. this way you can sit on the dock and loosen motor mounts, bear hug motor, then lay back lifting it off the back, onto you in a sense, then lay over onto the dock. one extra guy to assist just in case is all that is needed then.
OH, and use the lines from the boat to keep it secured to the dock while doing this little maneuver.
Pre planned this is a simple step. I have even done 150 lbs by myself this way.
I am 31, young laddy! but I was nailed by lightning too, and did this when hurt badly yet.
Maybe this will help ya, maybe not, but figured I would pass the info.
Mac
Quote from: MacGyver on November 26, 2012, 10:50:30 PM
Brackish,
Have a idea, it is what I do at work to get them off. First tie a line to it, long enough to do the following steps.
Put boat backed into slip. this way you can sit on the dock and loosen motor mounts, bear hug motor, then lay back lifting it off the back, onto you in a sense, then lay over onto the dock. one extra guy to assist just in case is all that is needed then.
OH, and use the lines from the boat to keep it secured to the dock while doing this little maneuver.
Pre planned this is a simple step. I have even done 150 lbs by myself this way.
I am 31, young laddy! but I was nailed by lightning too, and did this when hurt badly yet.
Maybe this will help ya, maybe not, but figured I would pass the info.
Mac
Thanks Mac, I'll end up doing something similar. Complicated by the fact the my dock is a floating dock. the main pier is fairly stable, but the finger reacts to any shifts in weight. also nothing high to tie off to. But I plan to back it in, fender it tight to the finger pier and sit on the main pier to remove it with a safety line to my stern rail. I think two of us can get it OK doing that. Then a cart to get it to the truck so I can take it to my shop to service it. Was last serviced three years ago when I got the boat, however that is probably less than 50 operating hours. Currently running a little rough at low speed additionally oil needs to be changed, maybe change the impeller as a preemptive measure.
When I take it off it won't go back. Lighter Sail Pro will replace it.
Wonderful feedback, thanks all!
I bought a used 23 with a 8 hp Honda. It was way overpowered. Barely crack the throttle and the boat simply squatted. Not at all certain about the gps I have but it reflected 7kts. I now have a smaller motor with electric start.
Brian:
Hi. I'm gonna echo with most of what's been written above. I have an 1988 8hp Nissan 2 stroke on my 23. Weight is not the issue but it's nowhere near the weight of a 4 stroke. Because I occasionally need to motor into opposing wind and tide (narrow channels) I like the available power of the 8 hp. For motoring in calm wind, I run it at about 1/3 throttle. I'd like a 4 stroke someday but this motor is too darned reliable. If I were to replace it, the 6 hp Sailpro would be my choice.
Bob23
I have a 9.9 Honda with generator and start button. PO loved it as he could motor around the lake to his heart's desire. I find it too heavy, but I like using sweeps to get out of the port so I guess I am kinda weird.
Ah, sweeps on a CP23. A man after my own heart.
bob23
I was planning to post this very same question, so I, too, have benefitted from the great feedback you received. I inherited a 9.9 four-stroke that came with my boat. I am not happy with it because it is so heavy. That motor actually causes her to list to port while she is resting in her slip! Ridiculously heavy and really more power than she requires.
I evaluated two motors this summer for my CP-23. The boat came with a 1980 Evinrude 9.9 and I have a 1979 Johnson 6hp that I used to use on my Rhodes 22. I found that the additional weight of the 9.9 made the boat list to one side. I also found that when I used more than about 60% power the boat would become overpowered and start to squat at the stern. The 6HP seems to be the best choice for my boat. It trims much more nicely in the water and I get a nice cruise speed at a setting of about 75% power.
I really like the older Johnson/Evinrude motors from the 60s and 70s. They are inexpensive to buy and maintain also very reliable and smooth running if cared for. They are also easy to find in the great lakes region. The biggest weakness I see is that they would not be a good choice for salt water. I boat on Lake Erie so this is not an issue for me.
If I had to buy something new I would probably get one of the Tohatsu 6 hp Four-Stroke Outboards. A friend of mine bought one last year. The only drawback I have found compared to the older motors is that they are a little noisier and vibrate more since they only have one cylinder. Of course this comes with there benefits as well, no oil and gas to mix and much lower fuel consumption.
Chris
I ended up with the Tohatsu 6 hp Four-Stroke Outboard (Sail Pro). Will be shaking it down tomorrow.
Good luck! Let us know how it goes.
Great choice! I've had good luck with mine, plenty of power, even though I got the 4 hp, and the more I used it the better it ran. Vibration has been mentioned. Hopefully
you have a good motor mount already. I put on a new heavy duty mount and epoxyed in a big 3/4" plywood backer plate. This had made a difference by taking care of most of the motor
vibration. I'm not sure if the sail pro comes with the big prop already, if not, that'd be good to get, it makes a big difference too.
"I'm not sure if the sail pro comes with the big prop already, if not, that'd be good to get, it makes a big difference too."
Yes, it comes with the elephant ears high thrust prop.
Shawn
What is the proper prop size for a 9.9 on a cp23?
Bobl
At 104 lb, that 9.9 four stroke is a bunch of weight. I'm old enough to shake lifting a 56 lb, 5 hp two stroke up onto the mount once a season.
It's a shame two strokes were legislated out of existence, they inefficiently burn such a small percentage of the fuel and oil cracked.
The motor mount says good for 20 hp.
I don't have any good ideas for an O/B on a 23 foot.
When I bought my 1996 CP-19 the boat next to it was a 23 with a diesel in it. Pretty rare.
...I just grabbed a book off the shelve, flipped a few pages to find what I was looking for-->"Looking ahead to times when Guba II would land and maneuver on unknown lakes, Archbold had a nine-horsepower outboard motor installed in a rear tunnel hatch. This gave the big plane the ability to slowly approach the shoreline with it's Pratt & Whitneys switched off, to turn on a dime, and even to back up..."<-- PBY: The Catalina Flying Boat, Roscoe Creed, author. The PBY built in 1935 weighs empty 21,000 lb. and 9 hp is good enough to move that aeroplane.
skip.
The common question. " What's the maximum horsepower I can use on my boat? "
On single hulled vessels simply take your boats length [not including pulpits, transom brackets, swim platforms and the like] and multiply it by her beam at the transom. [Don't use maximium beam at mid ship]. An 11 foot dinghy with a 3'-3" beam at the transom is 35.75 square foot. Say 36 square foot. For a displacement boat this gives a 5 hp [3.7 kw] which would drive her at a good 4.5 knots. On my CP-19 with the 5 hp two cycle, I can see 4.5 knots and sometimes almost 5 knot. With the sails and the motor 6.3 knots is possible.
I spared us of the tedious calculations, I found a chart. If it is too small hold Ctrl key down and tap + to enlarge chart.
skip.
(http://i259.photobucket.com/albums/hh299/1930fordroadster/ComPac%2019/001-2_zps09e28dd1.jpg)
For maximum people on board= length of boat x beam divided by 15.
Other common question; " What size prop? "
Many people don't realize that the propeller's barely a hundred years old. John Ericsson~of Monitor fame~made one of the first attempts at using propellers instead of paddle wheels. At the time primitive propellers were about half efficient as paddle wheels. But at least they didn't get shot away or rammed to pieces.
Your prop will drive forward a certain distance for each complete turn. If it moves forward 10 inches, it has a 10 inch pitch. Since the prop is attached to a shaft and thrust bearing, it moves forward 10 inches, and pushes against the hull and that moves the boat forward 10 inches. A excellent reason for strong engine mounts and engine/mount beds.
Prop blades are twisted as you look at them on edge. When rotating say a 16 inch prop the inner part close to the hub travels 11 inches, the outer circumference at the tip travels 50 inches. You don't want the tip to be racing ahead of the inner part of the prop so you have to give the tips an angle so that the tip ends up at the same place as the blade root every turn. Carring this principle all the way down the length of the blade to the root gives props a typical looking twist. Remember that the pitch of a prop is not the same as its blade angles. These angles vary all along the length of the blade to keep the pitch constant.
Propeller blades when driving the boat forward and rotating clockwise when viewed from the stern is right-hand, counter clockwise when viewed from the stern is left-hand.
Propeller blades are narrowest at the root, and broadest about 2/3 of the way out. The amount of blade area that can be driven by a given power is limited so you have to distribute the area where it will do the most work. [I have wondered for years why engines don't have an automatic variable speed automotive type transmission attached to them driving a propeller. Power is limited.]
How many blades? Best is one! only because there are no other blades distributing the water flow ahead of it. But they can not be balanced. Two blades are reduse drag but need huge diameter to get all the blade to drive efficiently. So its three blade is the logical choice. This configuration has proved best for balance, area, and efficiency. Four blades yield more area with less diameter but the extra blade makes things closer together and scramble up each other's water flow. Efficiency drops.
Less blades reduce vibration. A three blade at 1000 rpm passes under the hull or strut 3000 times a minute or 50 times a second. A four blade at 1000 rpm makes 4,000 'bangs' a second or 66 cycles of vibration.
more later.
working on the answer
"What is the proper prop size for a 9.9 on a cp23?"
I would think a 6 or 7" pitch prop would be about right. The 6hp Tohatsu Sailpro prop is a 6" pitch. See if there is a "high thrust" version of whatever engine you have and grab the prop it uses.
Shawn
PropCalc suggested 8.6 Diameter, 5.5 Pitch for a three blade and 8.1 D and 5.4 P at 5,700 RPM 4 blade using my assumptions on the two stroke. It also showed 9.8 horsepower is more than the boat needs, but that is what came with the boat. I chose the 8.7 D, 5P four blade 3B2W645110 high thrust and am happy with it.
I am not sure about the gear ratio of the 4 stroke, but shorter pitch is better for displacement hulls. The short pitch allowed the boat to go slower at idle speed - minimum was too fast with a long pitch. Acceleration is better with short pitch when you need to avoid somebody's navigational mistake. RPMs are a little high wide open, but there is little reason to do full throttle. 9.8 HP is more than we need for the hull speed of the boat, so trying to go faster wastes lots of power and fuel. I back off a little and don't see much difference in boat speed. The short pitch has been also helpful pushing into a heavy wind and when towing racers to the course.
My C23 came with a 8 hp Honda. Aside from being overpowered, it does affect the balance. With the rudder lifted as high as it will go a portion remains in the water. When the motor is removed the rudder blade clears the water by about four to five inches. No idea as to how it affects the balance when under sail but it must do so.
Quote from: briano on November 30, 2012, 09:48:13 PM
I ended up with the Tohatsu 6 hp Four-Stroke Outboard (Sail Pro). Will be shaking it down tomorrow.
How did that motor work out for you? I'm thinking about getting one.