Fmicol
Active Member
Hello,i have a Karnic 2460 ,8m long with an inboard engine ,i would like to mount an outboard for emergency on the rear plateform please do some one have this experience?
Outboard size for emergencies
- Thread starter ostell
- Start date
neilards
New Member
hi i am new to the Yachting and Boating World, and new to boating, i bought my first boat just the other week, i need to get an outboard for it , but dont have a clue what size i need , if i post a photo of the boat could someone give me advice on best size outboard for this boat , i dont even know what sort of boat it is, would be grateful for some advice , thanks
ghostlymoron
Well-Known Member
17 footer needed 4hp, 22 footer better with 5hp. Long shaft or short shaft depending on mounting bracket.
prv
Well-Known Member
Welcome.
I'm sure people will be able to give you a lot of advice, including a suitable engine size - but probably best to start a new thread for it.
Pete
neilards
New Member
thanks ghostlymoron and pete for reply , will get photos and open new thread
thanks again
neil
thanks again
neil
William_H
Well-Known Member
One would go for a reasonable sized engine(6 to 10HP) in a long shaft for any sail boat up to 24 ft or so. I had a friend with an 8HP o/b on a 32 ft light weight racing sail boat. Apparently OK. However the compromise is if you want to remove the engine from the transom or outboard bracket when leaving the boat. They can get heavy and so a small o/b has advantages.
A long shaft gives you the ability to sink the prop lower before there is danger of motor being swamped by going to low in the water. Sail boats tend to have a greater rage of pitching especially in a head sea than MOBO so while an adjustable outboard bracket on the transom is OK a motor mounted in a well has advantages because being further forward it does not rise and fall so much in pitching.
My 21fter has a 6HP outboard on an adjustable bracket on the transom and has proved OK in all conditions I have met. but sailing is much better.
good luck olewill
A long shaft gives you the ability to sink the prop lower before there is danger of motor being swamped by going to low in the water. Sail boats tend to have a greater rage of pitching especially in a head sea than MOBO so while an adjustable outboard bracket on the transom is OK a motor mounted in a well has advantages because being further forward it does not rise and fall so much in pitching.
My 21fter has a 6HP outboard on an adjustable bracket on the transom and has proved OK in all conditions I have met. but sailing is much better.
good luck olewill
Tricia
Well-Known Member
I didn't read all the posts in this thread so someone may have already said something along these lines, sorry if I am repeating someone's comment.
I have a Sadler 25, and when our Volvo MD5 (7hp) inboard gave up the ghost we decided to go the outboard route. Originally we bought a used 3hp outboard, transom mounted it, but couldn't get one with a long shaft. It pushed us along at about 2/3 knots but in any kind of swell the outboard would bounce out of the water. Rob did some work for someone who, in payment, gave us a 5hp outboard with a long shaft. This is great, pushes us along at 4 knots even in a swell, but we really don't use it that much as Bluet sails like a dinghy and doesn't need much wind to push her along.
I have a Sadler 25, and when our Volvo MD5 (7hp) inboard gave up the ghost we decided to go the outboard route. Originally we bought a used 3hp outboard, transom mounted it, but couldn't get one with a long shaft. It pushed us along at about 2/3 knots but in any kind of swell the outboard would bounce out of the water. Rob did some work for someone who, in payment, gave us a 5hp outboard with a long shaft. This is great, pushes us along at 4 knots even in a swell, but we really don't use it that much as Bluet sails like a dinghy and doesn't need much wind to push her along.
neilards
New Member
hi, olewill thanks for the reply its not a sail boat i have it is lke a 17ft cabin cruiser , dont even know what make of boat it is, their is a plate with name of company on it , but i googled the name got a number of some company in Southampton, but the guy said they are not the same company and could not help at all. this is my 1st boat and i know nothing about boating what so ever ...were the outboard goes on the transom there is like a well behind the outboard it is like the outboard is encased , maybe you guys here know what this is called , i will get some photos of it and make a new post and maybe you could have a look , sure picture would give you more info than the way i am explaing it , sorry for that but it is my 1st boat and guess i need a book like boating for dummies lol, anyway mate thank you for the reply , its well informative thanks for your time
neilards
New Member
thanks tricia , that is good to know about the swell as were i am planning of going up round Torr Head which from what i have heard has very strong swell
neilards
New Member
these are the photos from the boat 3 are of the transom and think it is called well?? its like the outboard is encased does anyone have any idead about what type of boat it is ? and is 6 to 10 hp ok for this thanks
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charles_reed
Well-Known Member
I've quite frequently moved my 31' boat with 3.5 Tohatsu, but never above a Bf6. Most times on the rubber dinghy but once direct to the boarding ladder.
Usually at no more than 4kts in a calm and a fraction of that in a seaway - so it all depends on how far you intend to move the boat.
Usually at no more than 4kts in a calm and a fraction of that in a seaway - so it all depends on how far you intend to move the boat.
William_H
Well-Known Member
What you have there is an outboard well for the main outboard and a transom bracket for a standby outboard.
Now I think you asked about a motor to power the boat as the main. This probably should be in the range of 15 hp just to give you some excess of power into strong winds and waves and enable the boat to reach hull speed about 6 knots easily.
The mass of this engine will not be such a concern as it will remain in place. Although nice if you can lift it out of the water to minimise corrosion and weed build up. This will be a twin cylinder so much quieter/smoother.
Now for the stand by or emergency motor a much lower power would be appropriate being lighter so you can stow it in the cabin and only fit when needed. Don't forget to attach a rope tied to a strong point (lanyard) to the motor in case you drop it in the water. This will probably be a single cylinder engine noisy but hopefully you won't need it much.
The transom bracket is adjustable so that you can push the motor down deep enough that it will not lift out of the water (cavitate) when the boat pitches on waves. I have been surprised with my little 6HP Johnson that it can be so deep that the under side of the power head touches the water of a following wave even goes under a bit but providing you are going forward it does not get drowned. What you need to do is try the standby engine out under real conditions to see just what performance you can expect.
For starters however I think you should concentrate on the main engine in the well. You may get an electric startwith decent battery charging capability. Careful maintenance of a good engine should mean you won't need that standby engine. Do fit a VHF radio so if you get a failure you can hopefully get a tow. It is interesting that here outboard engine(s) are making a comeback from inboards even diesels as they become fuel efficient quiet and pwerful on much larger MOBO. good luck olewill
Now I think you asked about a motor to power the boat as the main. This probably should be in the range of 15 hp just to give you some excess of power into strong winds and waves and enable the boat to reach hull speed about 6 knots easily.
The mass of this engine will not be such a concern as it will remain in place. Although nice if you can lift it out of the water to minimise corrosion and weed build up. This will be a twin cylinder so much quieter/smoother.
Now for the stand by or emergency motor a much lower power would be appropriate being lighter so you can stow it in the cabin and only fit when needed. Don't forget to attach a rope tied to a strong point (lanyard) to the motor in case you drop it in the water. This will probably be a single cylinder engine noisy but hopefully you won't need it much.
The transom bracket is adjustable so that you can push the motor down deep enough that it will not lift out of the water (cavitate) when the boat pitches on waves. I have been surprised with my little 6HP Johnson that it can be so deep that the under side of the power head touches the water of a following wave even goes under a bit but providing you are going forward it does not get drowned. What you need to do is try the standby engine out under real conditions to see just what performance you can expect.
For starters however I think you should concentrate on the main engine in the well. You may get an electric startwith decent battery charging capability. Careful maintenance of a good engine should mean you won't need that standby engine. Do fit a VHF radio so if you get a failure you can hopefully get a tow. It is interesting that here outboard engine(s) are making a comeback from inboards even diesels as they become fuel efficient quiet and pwerful on much larger MOBO. good luck olewill
neilards
New Member
brilliant olewill , now i know what to be getting on with, this information is what i have been looking for, i was looking online last night at vhf radios , so will be getting 1 of them fitted.,, i contacted a sailing club here that offers sailing and power boat courses , they have told me none running at the moment but will be starting sometime in spring and will let me know, i wanted to get the boat ready but made a rule before even bought it that i would take a course 1st to get the basic rules and safety for out on water, thank you again olewill for not just this information but for your time , gentleman thank you
neil
neil
neilards
New Member
thanks charles for the reply and your time
neil
neil
RIBW
Well-Known Member
View attachment 55742
Of no direct relevance but here is a 5HP and a length of 'string' in action in Mevva!
Of no direct relevance but here is a 5HP and a length of 'string' in action in Mevva!
neilards
New Member
wow just goes to show how much power is in these we units
doug748
Well-Known Member
Don't buy any engine till you are sure it will fit and:
a) Has a full range of movement, for steering, within the well.
b) Can be tilted clear of the water without bringing up short against the structure. You can see where a previous owner has cut away at the boat for this to happen with a previous engine
c) Suits the remote steering and throttle that you have in place/mind.
Older two stroke engines of c 10hp may be smaller than 4 strokes in the critical dimensions and will be inexpensive but will be smokier, which is esp noticeable when going downwind.
As suggested before I would repost in the Motor Boat section, where you will get a better response, and try and ID the boat as a first step.
a) Has a full range of movement, for steering, within the well.
b) Can be tilted clear of the water without bringing up short against the structure. You can see where a previous owner has cut away at the boat for this to happen with a previous engine
c) Suits the remote steering and throttle that you have in place/mind.
Older two stroke engines of c 10hp may be smaller than 4 strokes in the critical dimensions and will be inexpensive but will be smokier, which is esp noticeable when going downwind.
As suggested before I would repost in the Motor Boat section, where you will get a better response, and try and ID the boat as a first step.
neilards
New Member
hi dough , thanks for that advice , i have tried looking in f&q to see how i go about setting up new thread , but having trouble finding out what to do as it says to click on post new thread but can not see a link to do that, just new to this web site
neil
neil
doug748
Well-Known Member
Just get yourself to the Motor Boat Forum so you are looking at the list of threads. At the top above the threads is a red button - Post New Thread - click and off you go.