Outboard Size
- Thread starter OfflineTN
- Start date
It may get you to hull speed if you were going downwind in flat seas. I don't think that you will see anything near hull speed going upwind in a chop with a 5HP motor. I had a 25 footer weighing 3750 lbs and had a Honda 7.5 4 stroke on it. It was fine in perfect conditions. I switched to a 9.9 two stroke which was lighter and more powerful. If you are going to race your boat, the 5HP will be alright because it's light but you will need to power sail with the main if you want to make some speed going upwind. It will also stabilize the boat to help keep the prop in the water. Even a long shaft will be out of the water in a chop. In my opinion, look for a two stroke long shaft with at least 7.5 HP.
I raced a VERY similar boat - Merit 25 - for years using a Johnson Sailmaster 4 HP and experienced no problems whatsoever. The other guys with J-24s and Capri 25s were using the same or similar engine. All on inland lakes.
This has a lot to do with if it'll work for you or not. Where I sail, it wouldn't be enough. Where you sail, it might be alright. I use a 7.5 4stroke on my 25' MacGregor which weighs about the same. It does a good job in pretty much any conditions I want to be in. I've been forced to use the 4hp motor off my dinghy a couple times, and while it will move the boat alright on nice flat water it was painfully underpowered when the water was anything but perfectly flat, or when I needed a burst of power to maneuver in and out of a slip in a cross wind.
If you have nothing now, you're better off going bigger to start with than starting smaller and regretting it.
My B235 came with a 2-stroke 6. It only took me three sails to tell me it was not doing the job, so i went to a 4-stroke Honda 8 with 25-inch shaft. Life was much better after that.
Yamaha 8 hp 4 stroke, 7800 pounds of boat, loaded. Usually hit hull speed at the "start" setting on the tiller handle. And it pushed it just fine the entire coast of the country, from Texas to Annapolis. And up the Potomac. And all over the Bahamas.
I get 5.5 at that setting, hull speed is 5.6. Wide open throttle gains me exactly 1/2 knot
More throttle just squats the stern, and wastes fuel. As would more horse power.
If Yamaha (or anyone) made a 2 cylinder 4 hp 4 stroke, I'd put one of those in there. But they don't. And the 2 cylinder is SO much smoother running than a single cylinder.
People will tell you you need more "to go against a current" You aren't gonna exceed hull speed anyway, so if it's a 5 knot current, with a 6 knot hull speed, you're gonna make - ready? one knot. And I don't care HOW big the engine is- laws of physics don't change
Yes, I think it's plenty.
I get 5.5 at that setting, hull speed is 5.6. Wide open throttle gains me exactly 1/2 knot
More throttle just squats the stern, and wastes fuel. As would more horse power.
If Yamaha (or anyone) made a 2 cylinder 4 hp 4 stroke, I'd put one of those in there. But they don't. And the 2 cylinder is SO much smoother running than a single cylinder.
People will tell you you need more "to go against a current" You aren't gonna exceed hull speed anyway, so if it's a 5 knot current, with a 6 knot hull speed, you're gonna make - ready? one knot. And I don't care HOW big the engine is- laws of physics don't change
Yes, I think it's plenty.
It's not all about how fast you can push the boat. Sometimes it's all about how quickly you can get it moving, and how quickly you can get it stopped. With a sail boat that's already not the most maneuverable I'll take all the power I can get.
More motor may not push the boat any faster, or against a stronger current, but when you need to give the boat a quick burst to get into the dock, or a blast of reverse to stop it, etc. the bigger prop and extra torque of the bigger motors makes all the difference in the world. My boat will motor along at 5kts just fine in smooth water with either of my motors, but the little one is virtually worthless in reverse, and getting in and out of a crowded dock with a crosswind and lots of swells from powerboats was a nightmare. I regularly visit the same dock in the same conditions single handed with the bigger motor and have no problems because i can stop and turn with ease to adjust my course. I know that if I start to drift I can grab reverse and pull back quickly for a second approach. I cant do that with the smaller motor.
More motor may not push the boat any faster, or against a stronger current, but when you need to give the boat a quick burst to get into the dock, or a blast of reverse to stop it, etc. the bigger prop and extra torque of the bigger motors makes all the difference in the world. My boat will motor along at 5kts just fine in smooth water with either of my motors, but the little one is virtually worthless in reverse, and getting in and out of a crowded dock with a crosswind and lots of swells from powerboats was a nightmare. I regularly visit the same dock in the same conditions single handed with the bigger motor and have no problems because i can stop and turn with ease to adjust my course. I know that if I start to drift I can grab reverse and pull back quickly for a second approach. I cant do that with the smaller motor.
Could be Plenty
I see a lot of J-24s with 2 or 3 HP motors. Depends upon your intended use, those guys are racing so it is all about the weight all they want to do is get in and out of the slip. If you are planning on motoring all day long to get somewhere (not usually the reasons guys buy J boats) I'd go with the smallest two cylinder motor you can find, Anything over 8 would be a waste of gas weight and dollars.
I see a lot of J-24s with 2 or 3 HP motors. Depends upon your intended use, those guys are racing so it is all about the weight all they want to do is get in and out of the slip. If you are planning on motoring all day long to get somewhere (not usually the reasons guys buy J boats) I'd go with the smallest two cylinder motor you can find, Anything over 8 would be a waste of gas weight and dollars.
We moved our Bristol 24 (displacement 6000 lbs.) with a 3.5 hp. We only used it to get in and out of port. We weren't too concerned with operating it in other than calm seas. If there are waves there is wind, and it was a sailboat so we sailed it whenever wind was present. But that motor was adequate for our purposes so I can't imagine that a 5 hp wouldn't be plenty for a boat half that weight.
I'm with skipper.
Tohatsu makes the "sailpro". I think it is a 6hp with long shaft, alternator and a high thrust prop. You will get hull speed at 3/4 throttle with that.
Yeah, well. If it's only for getting in and out of a slip/marina, and out to the race course not too distant (or leave early); then you don't need much outboard power. Better to have an engine that you can lift & maneuver easily; 2 or 3 hp. If you're going cruising and wish to power against the wind and sea for any appreciable distance, then something bigger, clearly.
Offline, TN;
Everyone will give you an opinion but as a former retired dealer from NC and VA, I use to deliver boats on the TN River to include Teligo (snaildarter lake), Ft. Loudon, Chattanooga and so on. I know the boat and the sailing area if that is where you are planning.
The J 24 is considered a racing boat and the more weight you have, the less speed. Most of the captains had no more than a 5 hp at max and most said that was plenty of enough power which I concur as I use to help race one at Smith Mt. Lake outside of Roanoke.
You do have some current in the river but not enough to make a difference and as for the wind, it is less than near the coast. Actually for a 20 to 24 footer that 5 hp would be fine; however that might be different at the coast where winds are higher and more steady plus the current. A good example is Willougby Spit near Norfolk at the beginning of the James River. Not only current but that is a major shipping lane to include subs and the 5 hp would be under powered for a J 24. A lot depends where you are going to sail and I would assume on the TN River outside of Chattanoogo. By the way there are a couple of sailing clubs that I remember and maybe you could get there advice as local knowledge is the best in your case.
Crazy dave condon
Everyone will give you an opinion but as a former retired dealer from NC and VA, I use to deliver boats on the TN River to include Teligo (snaildarter lake), Ft. Loudon, Chattanooga and so on. I know the boat and the sailing area if that is where you are planning.
The J 24 is considered a racing boat and the more weight you have, the less speed. Most of the captains had no more than a 5 hp at max and most said that was plenty of enough power which I concur as I use to help race one at Smith Mt. Lake outside of Roanoke.
You do have some current in the river but not enough to make a difference and as for the wind, it is less than near the coast. Actually for a 20 to 24 footer that 5 hp would be fine; however that might be different at the coast where winds are higher and more steady plus the current. A good example is Willougby Spit near Norfolk at the beginning of the James River. Not only current but that is a major shipping lane to include subs and the 5 hp would be under powered for a J 24. A lot depends where you are going to sail and I would assume on the TN River outside of Chattanoogo. By the way there are a couple of sailing clubs that I remember and maybe you could get there advice as local knowledge is the best in your case.
Crazy dave condon
I got an 8 hp 4 stroke . I use it to pull out or to pull in my dock. Sometimes my Honey wants to motor around ,when there is no breeze. I went to Kingston,NY and that's a 10hr.(50 miles) trip with the motor running the whole time
A J24, I thought you'd want a 3.5, with no reverse. 
Seriously, what you put on it depends on where you are. I have a 4hp/4Stroke on my 23 footer and it's fine for getting us in and out of the Marina and back home if the wind dies and we are in a hurry. But it's an inland lake. If I had tides and currents to deal with, I'd have a beefier motor.
Seriously, what you put on it depends on where you are. I have a 4hp/4Stroke on my 23 footer and it's fine for getting us in and out of the Marina and back home if the wind dies and we are in a hurry. But it's an inland lake. If I had tides and currents to deal with, I'd have a beefier motor.
I agree... a set of sweeps would even suffice. This boat is very light through the water... it will consistently exceed "hull speed" under sail. Theoretical hull speed really doesn't apply for this one design.
It's a big racing class... the crew pulls the kicker off and stows it down low near the keel to help lower center of gravity for performance.
http://www.jboats.com/j24-one-design-sailboat
Note the PHRF ratings..... well ahead of larger full displacement vessels: http://www.cruisingfleet.org/phrf.html