Com-Pac Yacht Owners Association

Com-Pac Model Specific Discussions => CP-19's => Topic started by: crazycarl on April 26, 2011, 01:45:57 PM

Title: Which O/B?
Post by: crazycarl on April 26, 2011, 01:45:57 PM
I have 2 outboards to choose from for our 19.  A 5hp 25" shaft Nissan 2-stroke, (probably from the late '90s/early '00) or a 2009 Tohatsu  4hp-4 stroke.  The 5hp came with the boat.  The 4hp I purchased new for our previous boat.  I like the cleaner burning 4-stroke and the internal/remote tank feature, but I also like the longer shaft of the 2-stroke.  We mainly sail inland lakes, with the occasional sail on lake Michigan.

Since we haven't had the chance to splash the 19 yet, I'm not familiar with it's sailing characteristics, so input would be appreciated. 

With 4 outboards in the garage, I need to make a decision, and let 2 of them go.

Thanks in advance,   Carl
Title: Re: Which O/B?
Post by: Billy on April 26, 2011, 03:17:51 PM
what is the weight difference?
lighter is better

4 strokes burn cleaner & usually make less noise. 2 strokes are lighter and more power but a pain to mix the gas & oil.


if you mostly sail inland lakes I would go w/ the newer motor (4 stroke, shorter shaft, probably lighter). You only need the long shaft in really rough water.

Nissan & Tohatsu are the same motor just a different sticker. I used to have a 2.5 hp 15" shaft yamaha on my 19 and it did just fine (in calm water). big waves in theGilf of Mexico would make the prop come out and osilate. It would also come out when I went forward to raise/lower the sails. Now I have the sail-pro tohatsu 6 hp 25" shaft and it is almost too long...ALMOST

I say go w/ the newer smaller one.
Title: Re: Which O/B?
Post by: wes on April 26, 2011, 05:18:53 PM
I have the Mercury 5 HP 4-stroke, which is also a rebadged Tohatsu. Mine is a 2000 model. "Regular" long shaft (around 20" I think). It is about perfect for my 19. More horsepower than I will ever use for lake sailing - don't know what all those guys with 9 or 10 HP motors are doing with all that power (towing water skiiers at 5 knots? :). It is reasonably quiet (not as quiet as a Honda, though) and very reliable IF you feed it Sta-Bil in the fuel supply religiously. Omit the Sta-Bil and you will regret it. Those tiny carb jets are prone to plug up if the fuel gets old and/or is unstablized.

- Wes
Title: Re: Which O/B?
Post by: skip1930 on April 26, 2011, 07:11:55 PM
For speed when sailing the lightest engine hung on the transom. The more you push the stern into the water the slower she sails.
For best and cheapest running the 4 stroke. No mixing $$ oil.
For me it's a Mercury 5 hp 2 stroke 5000 rpm standard length shaft 45 to 50 lb? but 2 inches further down in the water and 2 inches back off the transom so it's not so close to the back of the boat. Wes...I thought the Merc 4 stroke was 6 hp.

Interestingly enough she'll move 5.6 knots with the iron horse, and can sail that fast as well with the right wind.  So the sails are making 5 hp?
For every 15 lb of wind pressure on the sails = 1 lb push at the keel, generally speaking about sail boats.

skip.
Title: Re: Which O/B?
Post by: Billy on April 26, 2011, 07:37:12 PM
Quote from: skip1930 on April 26, 2011, 07:11:55 PM
For every 15 lb of wind pressure on the sails = 1 lb push at the keel, generally speaking about sail boats.



Interesting!

yea, my 6hp is almost too big, ALMOST.
Title: Re: Which O/B?
Post by: wes on April 27, 2011, 06:29:57 PM
Skip - Mercury offered (maybe still does) the 4-stroke in both 5 and 6 hp versions. I have the 5. I have always suspected that they made them all the same, tested them at the end of the assembly line, and put a 6 hp sticker on the best ones :).

- Wes
Title: Re: Which O/B?
Post by: Shawn on April 27, 2011, 08:18:48 PM
Wes,

I have read that the 4,5 and 6hp are the same basic engine only the carbs are different. Some people put the 6hp carb on the other units.

Shawn
Title: Re: Which O/B?
Post by: Salty19 on April 28, 2011, 10:36:43 AM
Wes, I think a lot of us use larger O/B's is because it was either convenient or cheap to do so.    Also a lot of the 6hp o/bs are really 4-5 hp with different tuning (same weight).  Same goes for 8hp motors...often they are 6hp with tuning changes.  No add'l weight.  Now the 9.9s are just beasts and likely do not belong on a small sailboat (strong river currents notwithstanding) due to weight.

With that said, I agree that you don't need much to power these boats. I would imagine 3hp would be enough for lake sailing a CP19.  I use an 8hp Yamaha on the 19 which propels the boat at or slightly over 6 knots SOG. Nice for when the storm clouds suddenly pop up and the dock is a few miles away, but 98% of the time is overkill.