Com-Pac Yacht Owners Association

Com-Pac Model Specific Discussions => CP-16's => Topic started by: JonnyB on June 10, 2014, 07:48:28 AM

Title: CP-16 Outboard Delimma
Post by: JonnyB on June 10, 2014, 07:48:28 AM
I happen to be in possession of two, brand-new-in-the-box outboards, and I'm not sure which one to keep. I'm hoping some of you will share your wisdom and experience.

I sail a CP-16 in the Tampa Bay area. We have a few passes into the Gulf that flow like a river (4 knots?) when the tide is transitioning.

Mercury 4ML, 4 hp, long shaft (20"). 4-stroke. 59 lbs, true F-N-R shifting
Suzuki DF2.5, 2.5 hp, short shaft (15") 4-stroke, 30 lbs, "spin-around" for reverse

Thank you all.
Jon

P.S. Shout out to Sterling, who towed me to the boat ramp Sunday when my (old) outboard seized up. I think he has pictures of the rescue operation! Thanks, Sterling.
Title: Re: CP-16 Outboard Delimma
Post by: atrometer on June 10, 2014, 07:58:44 AM
I have a Honda 2,0 hp air cooled long shaft.  It pushes my CP16 to hull speed at about 1/2 throttle.  Since you can't go above hull speed that is more than adequate.  25#s 1 hour per tankful (.25 G), 20+ MPG
Title: Re: CP-16 Outboard Delimma
Post by: Craig on June 10, 2014, 09:01:36 AM
I think you will be happier with the 4 hp. Not for the power per se but more for having FNR. I had a "spin around" 2.5 on my WW Potter and it was a pain trying to back and fill in close quarters(like getting onto the trailer or into a slip under less than ideal conditions). The extra hp will be useful if you are fighting wind an current. Other than getting the motor off and on the extra weight should not unduly affect your trim. I had a 6hp Tohatsu long shaft on my Suncat(essentially the same engine you have just more highly tuned) and was glad to have the extra power available. Finally, the long shaft is a plus in choppy conditions when the prop may cavitate. Also lets you set the ob mount a little higher allowing easier control/steering.
Title: Re: CP-16 Outboard Delimma
Post by: NateD on June 10, 2014, 09:18:05 AM
That is a tough call. How about return both of them and get a 3-3.5HP long shaft with F-N? The extra 30 pounds of the 4HP will affect trim, the 16 likes to squat with any kind of weight aft. However, the more power (up to 4hp) the better, and long shaft is a plus if your going to be in any kind of waves (or go forward to drop an anchor). There may be times when having a reverse gear would be helpful, but I personally don't think it is worth the extra 20-30 pounds it adds to the stern of a 16. I never power load the boat (just float it onto the trailer with a line attached to the bow). When I'm in a slip or at a dock I just stand on the dock, grab a shroud, and guide the boat out and around so it's facing the direction I want to go, then hop in and put the motor in forward gear.

If I had to pick between the two motors you currently have, I guess I would lean toward the Mercury 4hp for the long shaft and the added power. But if the Suzuki was long shaft it would be a toss-up to me, trading off the weight for less power.
Title: Re: CP-16 Outboard Delimma
Post by: nies on June 10, 2014, 09:47:15 AM
Go for the Merc.,you wil never be sorry...........................nies
Title: Re: CP-16 Outboard Delimma
Post by: Floyd on June 10, 2014, 10:02:13 PM
More horsepower = better.

Go with the Mercury long shaft.

I consider my Lehr 5hp propane on my CP-16 to be minimally adequate on Tampa Bay.

The Bay does kick up more than people may think.

Floyd in Tampa Bay
Title: Re: CP-16 Outboard Delimma
Post by: skip1930 on June 11, 2014, 07:03:29 AM
4 hp two cycle sounds good to me.

skip.
Title: Re: CP-16 Outboard Delimma
Post by: Gerry on June 11, 2014, 07:25:03 AM
Keep the Merc...long shaft, 4 stroke and FNR.
Title: Re: CP-16 Outboard Delimma
Post by: Salty19 on June 11, 2014, 10:28:57 AM
I agree with Skip, a 4hp 2 stroke long shaft will give you power and low weight.  59lbs is a lot for a 16.  You will need appx 30lbs of weight (anchor, chain, etc) in the bow to maintain even sailing posture.

Since you're sailing in currents, you'll definitely want more hp than the 2hp can provide.
Title: Re: CP-16 Outboard Delimma
Post by: Craig on June 11, 2014, 05:40:40 PM
Not a lot of ballast to add/shift forward really. Essentially the same motor on the Suncat was not a trim problem for us.
Title: Re: CP-16 Outboard Delimma
Post by: capt_nemo on June 11, 2014, 10:25:02 PM
JonnyB,


Definitely Mercury 4 HP, long shaft, 4-stroke, w/FNR.

Shift a little ballast forward, ONLY IF NECESSARY. Experiment - try a small weight shift forward and see how the boat responds, both stationary AND underway.


capt_nemo
Title: Re: CP-16 Outboard Delimma
Post by: atrometer on June 12, 2014, 11:23:12 AM
A six (6) gallon water jug will give you about 50#s - and you may need some water!
Title: Re: CP-16 Outboard Delimma
Post by: Salty19 on June 12, 2014, 05:45:03 PM
Quote from: atrometer on June 12, 2014, 11:23:12 AM
A six (6) gallon water jug will give you about 50#s - and you may need some water!

Yep, sounds about right. Those Suncats with a foot wider beam give more support to the stern than 16's do. My old 16 squatted with a 43 lb motor and 200lb captain (zero items stored aft) and sailed way better with heavy weight forward.  I have no doubt forward weight will be essential with a 59lb motor, unless the captain is short and slim.

Title: Re: CP-16 Outboard Delimma
Post by: MacGyver on June 12, 2014, 07:42:48 PM
Quote from: Salty19 on June 12, 2014, 05:45:03 PM
,unless the captain is short and slim.



Like a short version of kickinbug???

Mac
Title: Re: CP-16 Outboard Delimma
Post by: kickingbug1 on June 12, 2014, 10:39:55 PM
  hmmmmm
Title: Re: CP-16 Outboard Delimma
Post by: ChuckO on June 14, 2014, 07:29:01 PM
Ahoy ... Good question!  As with so many boat things ... It depends on where you are using it and where you are going to use it  ....  it sounds like you need the power.  I have owned both ...  on a lake the 3.5 would work well, but with the tidal flow it would appear with the wind in your face  ... you would need to wait for the tide change if you wanted to move the boat.... so .. the smaller motor will not meet your needs ... don't kid yourself.

As the old sailor said "I'd rather be on the beach and wish I was at sea than be at sea and wish I was on the beach".

ChuckO
Charleston, SC
Title: Re: CP-16 Outboard Delimma
Post by: jpfx on June 16, 2014, 12:31:56 PM
following on from chuck o above.
however, if this OB this the one that is marketed as mercury, nissan & tohatsu AND is the same OB for 4, 5 & 6HP except for a carb change, then...
I spent a lot of time researching what would be a suitable smaller alternative and I'd use the suzuki in a skinny minute vs. the 5HP nissan I have. the reason being the weight and the resulting imbalance.
I'm sure the smaller OB will run a CP-16 at hull speed and tide is going to make no difference. if the tide is running faster than hull speed in the opposite direction then you're going to go backwards no matter how big the motor. you just have to 'kick it old school' and plan around the tides. there's many places around the world where tides aren't as mild and going against them is foolhardy or worse.
Title: Re: CP-16 Outboard Delimma
Post by: Salty19 on June 16, 2014, 04:10:55 PM
Quote from: ChuckO on June 14, 2014, 07:29:01 PM

As the old sailor said "I'd rather be on the beach and wish I was at sea than be at sea and wish I was on the beach".

ChuckO
Charleston, SC

Words to live by.  I've heard a similar version..."I would rather be in the boat with a drink on the rocks than in the drink with the boat on the rocks".
Title: Re: CP-16 Outboard Delimma
Post by: Craig on June 16, 2014, 06:57:22 PM
Theoretical hull speed is calculated as: HS=1.34xsq root of LWL. Note that I said "theoretical" since there are many variables (such as the condition of the bottom). Wave action can be a factor as well, not so much on theoretical hull speed per se but as a factor preventing it from being reached if sufficient power is not available. Displacement boats CAN exceed hull speed as in surfing or even when towed. With sufficient power a displacement boat can exceed "hull speed" it is just not economical to do. All that said, if I have to punch thru waves or fight wind I want as much power as I can reasonably carry. Its not so much about "most of the time" it is about those critical "other times" (to echo previously expressed sentiments)!
Title: Re: CP-16 Outboard Delimma
Post by: JonnyB on June 26, 2014, 05:25:24 PM
Thanks all, for your input. On a side note, I found my original CP-16 owners manual yesterday and it recommended a "3 to 4 hp short shaft." For what it's worth, I'm leaning toward the heftier Mercury 4 hp. My next step is to upgrade my motor mount to something 4-stroke compatible.

Thanks again!
Jon