Choice of kicker size for a 22' Cruiser?

W

Warren Glaze

New member
Your opinion please:
Have just bought "Ripple", a 22' Cruiser with a 90hp Honda but no kicker. Am considering an 8hp Honda but since the 15hp Honda is only 12 lbs. heavier, the same basic size and almost twice as powerful, what do you think about selecting the latter?
I am an old former 42' sailboat owner and like to cruise along remote shorelines at hull speed (5-6 Knots) and thought the 15 would do that with more grace than either the 4 cylinder 90 idling, or the 8 working too hard. Do you think the 15 would be slow enough at idle to troll for salmon?
I would be grateful for your opinion.
 
My feeling is that unless you get a second engine that is large enough for planing (and preferably propped accordingly if it's for regular use), then 15 hp isn't going to give you much (if anything) that 8 won't, because you'll be fighting physics at non-planing speeds (i.e hull length/speed).

But then I'm speaking in general and not specifically C-Dory.

Sunbeam
 
We had a 5 hp Mercury 2 cycle on our 22' cruiser. A few years back, we had an emergency and ran it for a few hours in calm water in the Gulf Islands BC. It went 4-5 knots [GPS speed] without strain. The Merc is dead now but I would buy a 6 hp 4 stroke to replace it, having had that experience with the 5 hp engine. The eight sounds fine. Also, I would want to minimize the weight on the stern.

BTW, I thought 1987 was the first year for the 22' cruiser.
 
I agree with sunbeam. You won't gain anything with the 22 by going to 15 hp. What you should look for on a kicker is a good smooth throttle, a good tilt lock, a good throttle lock. Make sure you can reach the tilt lock and lift the motor from inside the boat. I loved how well my nissan 9 ran and the large alt but it was hard to get to the release for the tilt lock while in the boat.
 
The best kickers are high thrust--larger props and lower pitch, ideal for displacement speeds--which will be less than 7 mph in the C Dory.

8 hp is plenty of this. I go with 3 to 4 hp and find it is OK for a 22.
 
If I were going to slow cruise with a kicker I would stick to at least an 8 hp. A twin cylinder 8hp is going to be much smoother than a single cylinder 6 hp.

Happy boating,

Karl
 
My single 6 hp Tohatsu 4 stroke was very smooth and quiet. It was a single cylinder. Tohatsu price can't be beat for the small engines. They re-label them as mercurys and Nissan's for more money.
 
As a rough rule of thumb, in displacement mode, you need approximately one horsepower for every five hundred pounds of weight. So if your boat weighs 3,500 pounds, you only need a 6 or 7 HP outboard. As the others have stated, anything more than that is wasting money on the price of the outboard, as well as you will be paying for the greater gas inneficiency of your main engine due to the added weight (creating drag) on your stern. That said, I found something really interesting when using a 4HP Yamaha 4 stroke on my CD 16 Cruiser. There was only a marginal improvement in top speed between running at approximately 15 percent throttle and WOT! So if you only cared about running at say, 85 percent of hull speed, Dr. Bob is probably correct about a 4 HP. That would be a good choice for trolling, and not bad for getting you home in benign conditions. The one exception to this, however, is the amount of current you are bucking. If you frequent conditions with heavy currents, such as in rivers and ocean inlets, you might want to consider a larger engine -- as much as 8 HP.

Rich
 
I have a 9.9 Yamaha high thrust which I really like. Not much more in weight than their 8hp. It also has a small alternator which helps. Karl is correct about twin cylinder vs single. A buddy of mine has a 8hp Tohatsu on his CD-16, good motor but the tilt bar keeps letting go at speeds and his kicker is always dropping down. Has not hurt anything yet but sure is unnerving to hear a bang while scooting across the water.
 
Hey Chuck, great point about the tilt lock. We have to wrap our 6hp tohatsu tilt lever to keep that from happening on our boat. I don't think I would want to buck a strong chop in a remote area with our 6hp for very long.

Karl.
 
I'd get a size that allowed you to reach your desired cruising speed at half throttle or less so you can enjoy the quiet solitude of those remote shorelines, and I'd make darn sure it had electric start and tilt.

I'd also put a remote throttle on it and a steering tie bar so I can sit in the cabin and cruise along even when it's nasty out. ;)
 
I have a honda 9.9 that is all electric. Its a decent motor, although if i were to do it again I would go with a yami T-8 if i could find one , or a 9.9.The honda carb has given me fits in the past(mine is 06) and typically needs a carb rebuild yearly. I would also be concerned that a 15 hp would idle down to be slow enough for salmon fishing.
 
I have a Honda 15 hp on my Hewescraft Ocean Pro 22 about 4500 #s loaded and have absolutely no problem trolling as slow as 1 mph and will push up tp 6.9 mph depending on wind,waves,and current. Main motor is Honda 225.
 
I had the same question last spring. I have a 22 cruiser with Honda 90. After reading comments on the C-Brat website and talking to Les Lampman, I went with a 15 HP Tohatsu long shaft manual start with charging capabilities. Cheap, reliable and light. Les did suggest electric start but I went for simplicity.

We used it all last summer, fishing and cruising along the Sunshine Coast up to Desolation Sound and had no problems. It is light enough for me to handle and pushes the boat well. I have even played around with it in rough water and wind. It does move the boat. In rough windy condition steering is a bit of an issue but i expected that. To date I have not had the locking issues some folks talk about when the motor is tilted up. As well I have it mounted right on the transom with no extra fitting. Fewer holes in the boat makes sense to me.

The only issue I had was, the Honda's plastic gas line connector snapping because I attempted to lower the Honda when the kicker was tilted.....live and learn.
 
5 Hp Merc 2 stroke on our 22 cruiser gives us 4.5 to 5 mph at half throttle,
full throttle, barely 6 mph.
We have a removable steering bar.
I like the Merc's 40lb weight, shallow tilt settings, integral fuel tank, as well as built in connector for aux tank.
 
What would really be interesting is for someone with a minimum 4 HP kicker on their CD 22 to show a power applied/speed achieved curve for their boat factoring out current and wind, for example:

Boat type: C-Dory 22 Cruiser
Total weight (boat, motors, fuel, persons, people, gear)= 3,500 lbs
Kicker: 8 HP Honda Long Shaft Electric Start

Idle...................4.8 mph
20% throttle.......5.2 mph
40% throttle.......5.3mph
60% throttle.......5.4 mph
80% throttle.......5.5 mph
100% throttle.....5.6 mph

This would help many new and existing forum users in kicker selection. Unfortunately, I won't have access to my boat until the end of May, but it will be a fun project for the summer.

Rich
 
Couple of thoughts-

While 15 is overkill, and 8 is plenty, you might consider Suzuki's new fuel injected 15. At around 105 pounds it is very light weight for a 15, and fuel injection is a no brainer in today's E10 world.

A note about current: Hull speed is the theoretical speed a boat can travel through the water at displacement speeds. The maximum speed is limited by hull shape and design and other factors. The rough number as I recall is square root of the waterline times 1.35. On a 22 Cruiser figure a waterline of 20', whose square root is 4.47, times 1.35 = 6.03.

So the maximum hull speed through the water is six knots. Now, if you are traveling against a 6 knot current, your effective speed over ground will be zero. If you're traveling against a 7 knot current you'll be going backwards, and it won't matter if you have an 8, 9.9 or 15 horse motor on the back.

As Mr Scott says, "you canna change the laws o' physics". Hull speed is speed through the water. At displacment speed of 6 knots if you are going with a 6 knot current you'll be closing in on 12 knots speed over ground. Apply more power (15 horse) and above hull speed something has to give- usually prop slip and cavitation. You may burn more fuel, but speed increase will be (almost) non existent.

So bottom line, an 8 with a high thrust style prop would be a very nice kicker on a 22 C-Dory, and we've seen a number of 6 horse motors because of the 30 pounds of weight savings over an 8 / 9.9.

Hope this helps.
 
Matt Gurnsey":1khaj73b said:
Couple of thoughts-

While 15 is overkill, and 8 is plenty, you might consider Suzuki's new fuel injected 15. At around 105 pounds it is very light weight for a 15, and fuel injection is a no brainer in today's E10 world.

A note about current: Hull speed is the theoretical speed a boat can travel through the water at displacement speeds. The maximum speed is limited by hull shape and design and other factors. The rough number as I recall is square root of the waterline times 1.35. On a 22 Cruiser figure a waterline of 20', whose square root is 4.47, times 1.35 = 6.03.

So the maximum hull speed through the water is six knots. Now, if you are traveling against a 6 knot current, your effective speed over ground will be zero. If you're traveling against a 7 knot current you'll be going backwards, and it won't matter if you have an 8, 9.9 or 15 horse motor on the back.

As Mr Scott says, "you canna change the laws o' physics". Hull speed is speed through the water. At displacment speed of 6 knots if you are going with a 6 knot current you'll be closing in on 12 knots speed over ground. Apply more power (15 horse) and above hull speed something has to give- usually prop slip and cavitation. You may burn more fuel, but speed increase will be (almost) non existent.

So bottom line, an 8 with a high thrust style prop would be a very nice kicker on a 22 C-Dory, and we've seen a number of 6 horse motors because of the 30 pounds of weight savings over an 8 / 9.9.

Hope this helps.
Click to expand...

Matt,

A fuel injected 15 HP that weighs ony 105 pounds? -- that is phenomenal! If I were buying a new boat today, that is something I would seriously consider.

With respect to not exceeding hull speed bucking current -- while technically you are right, I think you forgot that about semi-displacement speeds. If a boat is powered by only sufficient horsepower to bring one's boat up to hull speed, then you are correct; one can't exceed displacement speeds while in a displacement mode. However, if you have more horsepower then what is needed, you'll go into a semi-displacement mode, and should be able to exceed hull speed by a certain degree. It will be inefficient to be sure, and honestly, I would not know how to quantify this, for example, it could only make a one or two MPH difference at a given level of HP. That is why I stated earlier that if a person needs an auxilliary who operates in heavy currents, one would not want to have any less than what one needs to bring one's boat up to hull speed. In some cases, a little extra horsepower would help.

Rich
 
C-Nile":3vu9b0ss said:
Matt Gurnsey":3vu9b0ss said:
Couple of thoughts-

While 15 is overkill, and 8 is plenty, you might consider Suzuki's new fuel injected 15. At around 105 pounds it is very light weight for a 15, and fuel injection is a no brainer in today's E10 world.

A note about current: Hull speed is the theoretical speed a boat can travel through the water at displacement speeds. The maximum speed is limited by hull shape and design and other factors. The rough number as I recall is square root of the waterline times 1.35. On a 22 Cruiser figure a waterline of 20', whose square root is 4.47, times 1.35 = 6.03.

So the maximum hull speed through the water is six knots. Now, if you are traveling against a 6 knot current, your effective speed over ground will be zero. If you're traveling against a 7 knot current you'll be going backwards, and it won't matter if you have an 8, 9.9 or 15 horse motor on the back.

As Mr Scott says, "you canna change the laws o' physics". Hull speed is speed through the water. At displacment speed of 6 knots if you are going with a 6 knot current you'll be closing in on 12 knots speed over ground. Apply more power (15 horse) and above hull speed something has to give- usually prop slip and cavitation. You may burn more fuel, but speed increase will be (almost) non existent.

So bottom line, an 8 with a high thrust style prop would be a very nice kicker on a 22 C-Dory, and we've seen a number of 6 horse motors because of the 30 pounds of weight savings over an 8 / 9.9.

Hope this helps.
Click to expand...

Matt,

A fuel injected 15 HP that weighs ony 105 pounds? -- that is phenomenal! If I were buying a new boat today, that is something I would seriously consider.

With respect to not exceeding hull speed bucking current -- while technically you are right, I think you forgot that about semi-displacement speeds. If a boat is powered by only sufficient horsepower to bring one's boat up to hull speed, then you are correct; one can't exceed displacement speeds while in a displacement mode. However, if you have more horsepower then what is needed, you'll go into a semi-displacement mode, and should be able to exceed hull speed by a certain degree. It will be inefficient to be sure, and honestly, I would not know how to quantify this, for example, it could only make a one or two MPH difference at a given level of HP. That is why I stated earlier that if a person needs an auxilliary who operates in heavy currents, one would not want to have any less than what one needs to bring one's boat up to hull speed. In some cases, a little extra horsepower would help.

Rich
Click to expand...

Correction -- I meant to state 'semi-planing' mode and not 'semi-displacement.' I think that the light weight and narrower beams of our boats makes exceeding hull speed without planing possible, but it would be interesting to hear from people about their experience on C-Dorys with larger kickers 10 HP and up as to the extent they can exceed hull speed of 6 mph on their CD 22's. My assumption could also be wrong, Matt, so it would be good for most of us to be educated on this subject. I could be way off base and not know it. This would actually benefit the group when selecting appropriate kickers for our boats in that it could save us money in not getting more auxilliary power than what we need.

Thanks.
 
The C-Dory hull shape is definately a variable in the equation, as it is a more easily driven hull. Actual performance numbers would be enlightening, especially at full throttle.

I've talked to a lot of kicker buyers who figure if 9.9 is good, 15 must be better, which isn't always the case. I'd probably make more money if I sold them the 15, but in most cases, they don't need it.
 
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