1) motor 2) size Is there any benefit to mount the outboard on the back instead of in the well ? And what are the negatives. Also I want to know if it would make sense put a 15 - 20 hp on the klet 7.6 or it would just be a waist of money. One other question does any body have schematic on the cabin table. Thank you Gene
Newbe with questions 1) motor 2)
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Gene,
I can't answer about the well but I'll say that the PO of my boat glassed in the well and mounted the kicker off the stern and it does well. As far as the size of the motor goes, anything past 8HP on your 24 footer would be a waste of money and displacement. Many folks will tell you that they use a 5 HP kicker on 25 footer and it will get to hull speed with no problems. Your hull speed is in the 6 knot range and I'd safely bet that you'd find the same. If you are looking for a motor, I'd suggest a 4-stroke. Not much heavier than a 2 stroke (if at all) and MUCH quieter.
I can't answer about the well but I'll say that the PO of my boat glassed in the well and mounted the kicker off the stern and it does well. As far as the size of the motor goes, anything past 8HP on your 24 footer would be a waste of money and displacement. Many folks will tell you that they use a 5 HP kicker on 25 footer and it will get to hull speed with no problems. Your hull speed is in the 6 knot range and I'd safely bet that you'd find the same. If you are looking for a motor, I'd suggest a 4-stroke. Not much heavier than a 2 stroke (if at all) and MUCH quieter.
There are two disadvantages to the well 1) if you cannot raise the motor out of the water while sailing, it will create quite a bit of drag and 2) it often takes up cockpit space
the ONLY advantage to a motor well is that you can usually enclose them and make your motor a bit more secure than your neighbors motor....
the 4 stroke motor in a 7 to 10 hp range will be about 25-40 percent heavier than the 2 stroke. its really an insignificant amount to the boat, but the motor bracket may take a beating if it isnt big/strong enough to handle the larger motor...
the 4 stroke motor in a 7 to 10 hp range will be about 25-40 percent heavier than the 2 stroke. its really an insignificant amount to the boat, but the motor bracket may take a beating if it isnt big/strong enough to handle the larger motor...
I have had 3 trailer sailed boats of 22, 23, 26 feet and all have had motors of less that 8hp. These motors were all 4 stroke and pushed the boat very nicely, even in very high winds.
A four stroke motor gets almost twice the milage of the 2 stroke. Finally, I've found that the main times I need to use the motor is when there is no wind and there is nothing worse that motoring in a cloud of oil smoke because of a 2 stroke motor.
Ray
A four stroke motor gets almost twice the milage of the 2 stroke. Finally, I've found that the main times I need to use the motor is when there is no wind and there is nothing worse that motoring in a cloud of oil smoke because of a 2 stroke motor.
Ray
I think that the 2x mileage advantage is way overstated. The fishing guides I deal with down here all have said the same thing on fuel efficiency - if you use your outboard a lot every day like they do, you will see better mileage, but not anywhere near twice as much. One study I saw even had 2 strokes getting better mileage at certain speeds than the same hp 4 strokes.
The main advantage I see for a sometimes user is that you don't have to pre-mix your fuel.
The main advantage I see for a sometimes user is that you don't have to pre-mix your fuel.
7000miles of cruising with a 25 footer, and an 8 hp 4 stroke, after 2500 miles with a 2 stroke on the same boat, tells me that the fuel savings are most definitely in the 2 times range, if not more.
Remember- on a sailboat, at displacement speeds, that engine is gonna be running pretty close to idle, NOT at the wot that the power boat users operate at.
Remember- on a sailboat, at displacement speeds, that engine is gonna be running pretty close to idle, NOT at the wot that the power boat users operate at.
Point taken, TSBB. From what I've read and heard, an idling or low speed 2 stroke will use more fuel than an idling or low speed 4 stroke.
There is a HUGE difference between different models of 2 and 4 stroke motors. Some 2 stroke motors will get better mileage than some 4 stroke, however generally speaking the 4 stroke will get a little better fuel economy, primarily due to the higher compression ratio's they run which leads to a cleaner and more complete fuel burn.
RPM also makes a HUGE difference. 4 stroke motors have more pronounced power bands where they operate at significantly higher efficiencies than other RPMs. If you are operating a 4 stroke motor inside it's optimal power band, then you will see really good economy, certainly better than a 2 stroke (probably in the 20% improvement range, not the 100% someone claimed). If however you run a 4 stroke far outside it's power band, and you compare it against a 2 stroke running in it's (broader) power band, the economy differences will likely be negligible.
That is also not factoring in age and wear on engines. 4 strokes that have weak compression will suffer performance and economy much faster than a 2 stroke, because a 2 stroke runs at a far lower compression ratio to begin with.
In short, in ideal conditions the only significant downside to a 2 stroke is pre-mixing fuel. Other than that, they are good engines that will last a very long time with very little maintenance.
One other point to consider. size for size, the 4 stroke will be MUCH quieter than the 2 stroke. With our 4 strokes, we could actually converse in the cockpit, which didn't happen with the 2's- same boat, engine running in a well.
I for one, will NOT go back for an engine for a cruising boat. Dinghies? Sure- 2 s are much lighter to handle, and don't have the problems of "how do I stow it on it's correct side". But you then have to problem of two types of fuel- straight gas, and a gas oil mix.
Trade offs.
I for one, will NOT go back for an engine for a cruising boat. Dinghies? Sure- 2 s are much lighter to handle, and don't have the problems of "how do I stow it on it's correct side". But you then have to problem of two types of fuel- straight gas, and a gas oil mix.
Trade offs.
Getting back to where you started. The boat was designed with a well, so the designer put some thought into it for a reason. The outboard in a well will behave much more like an inboard and the shaft will be sufficiently in the water at all times which will aid in performance especially in heavy seas. The motor in the well is easier to reach than an outboard hung motor. An outboard hung motor sometimes will come out of the water in heavier seas or if too many crew are sitting on the bow - not a problem with a motor in a well. The downside to a well mounted motor is that you cannot tilt up the motor out of the water as someone else pointed out, hence more drag, but most likely it is not on a racing boat anyway, so drag isn't such a both for day sailors or cruising folks. Sometimes, depending on the boat and design and ventilation features, you have to keep the hatch open to the outboard well or it will be starved of oxygen and will kill. Security, as pointed out, is better with a well. Also, unfortunately, the new 4-strokes won't fit into the well designed for a 2 cycle outboard without modification. In regards to HP......because sailboats are displacement hulls, they will only go so fast. So putting a larger outboard on it does not add to efficiency. One more point on the well verses transom bracket......The outboard on the transom will move weight further outboard on the stern while the motor in the well will not be so heavy on the stern, which is a good thing from a performance perspective and fore and aft hull trim.
You're absolutely right, 4pts. One study I saw compared several engines, same HP, same brands, 2st and 4st versions. The differences varied depending on the RPMs, and at some RPMs, the 2st was actually more efficient than the 4st.
As for reliability, I have a 1985 2stroke on my fishing boat. Knock on wood, it still runs great, and the last few trips, I've gotten between 3-4 mpg.
Most sailboats 26-27 foot down are displacement hulls that will only go so fast under power. When the bow starts to lift up at high speed, then the max speed under power has been achieved which will require backing off the power. It is like plowing thru the water hitting a wall of water until the bow is back down. Over the years, the largest I sold on any sailboat was no more than 10 hp. In additon, most transoms to include those well housings in the cockpit for the motors were only designed for motors no larger than 10 hp and on the older sailboats that is very well true. So a motor rated above 10 hp is doing more harm than good.
As for engines, EPA required all engines to be changed essentially to four stroke by 2006 due to pollution rules. Thus the heavier engine which there are pros and cons of course but fuel effiency is increased by the four stroke engines.
However, with ethonal now, I would suggest to all that you include the additives to help combat that ethonal but most important, let the engine run out of fuel so that the fine jets within the carb will not become fouled with fuel remaining in the carb.
As to the well housing in the cockpit, that was not seen on too many boats. First, the motor cannot be tilted upward thus barnacles, algae and so on can grow while in the water not to mention the drag as well when under sail. In addition, I had seen damage from engines bumping forward on the well housing wall mostly below the water line which needed repairing. In addition over the years, the water hitting the edges along the hull bottom actually wore down needing repair. This is why I stayed away from selling boats with that well housing in the cockpit.
Crazy dave condon
As for engines, EPA required all engines to be changed essentially to four stroke by 2006 due to pollution rules. Thus the heavier engine which there are pros and cons of course but fuel effiency is increased by the four stroke engines.
However, with ethonal now, I would suggest to all that you include the additives to help combat that ethonal but most important, let the engine run out of fuel so that the fine jets within the carb will not become fouled with fuel remaining in the carb.
As to the well housing in the cockpit, that was not seen on too many boats. First, the motor cannot be tilted upward thus barnacles, algae and so on can grow while in the water not to mention the drag as well when under sail. In addition, I had seen damage from engines bumping forward on the well housing wall mostly below the water line which needed repairing. In addition over the years, the water hitting the edges along the hull bottom actually wore down needing repair. This is why I stayed away from selling boats with that well housing in the cockpit.
Crazy dave condon
Sizing a motor so that it is just powerful enough to propel the boat at hull speed in calm water might leave you with less power than you want when wind and waves are pushing you backward. I have experienced 9.8 Hp on a Catalina 25 footer not being enough to make decent headway.
Interesting. I've NEVER had that problem with an 8 HP, on a boat displacing about 7600 pounds loaded, over many thousands of miles, from the tip of Texas around to the Chesapeake, and return, several times. And have NEVER run that engine at anywhere close to wide open throttle while cruising.
If against a current that is going 5 knots ( just to pick a figure) and the boats hull speed is 6 (again, picking a figure), you'll be making 1 knot...You aren't gonna go any faster with a 20 hp than you are with whatever gives you hull speed, be that 5 hp, or 8 hp, or whatever. Just ain't gonna happen. Now wind might be a tad different, but still- any engine capable of solid hull speed, will do just fine . It'll just take longer to get there.
If against a current that is going 5 knots ( just to pick a figure) and the boats hull speed is 6 (again, picking a figure), you'll be making 1 knot...You aren't gonna go any faster with a 20 hp than you are with whatever gives you hull speed, be that 5 hp, or 8 hp, or whatever. Just ain't gonna happen. Now wind might be a tad different, but still- any engine capable of solid hull speed, will do just fine . It'll just take longer to get there.
You're right as far as going straight ahead. But if maneuvering, a bit more power can be invaluable. Think about,for example, having to swing your stern around ASAP to avoid a collision, something along those lines. Still, you don't want too much weight on the back for other reasons. It's a balancing game.
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