what size motor for my boat?

scully222

Seaman Apprentice
Joined
May 1, 2007
Messages
33
I want to buy an outboard for my son's 12 ft aluminum Seaking rowboat. What size motor should I be looking at? I thought between 5-10hp. Would 5 hp not be enough to plane out or would 10 hp be too heavy and push the front way up? No sticker on boat.
 

ezmobee

Supreme Mariner
Joined
Mar 26, 2007
Messages
23,767
Re: what size motor for my boat?

A 9.9 would plane it. A 5 might with just one person. The max on that boat is probably 15. I would go with the 9.9.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: what size motor for my boat?

agree, 9.9 is popular, and will be easy to sell later.
 

fishmen111

Chief Petty Officer
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Feb 1, 2008
Messages
637
Re: what size motor for my boat?

Agree also. Around here, a lot of small lakes have a 10hp limit. 9.9s are very popular.
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Re: what size motor for my boat?

Had a 12'er with a 9.9 and with one person that thing would haul, did really well with 2 people too.
No sticker as in HP limit or registration numbers?
Where I am if you have any power source other than human it needs registration numbers on it, even a trolling motor.
 

scully222

Seaman Apprentice
Joined
May 1, 2007
Messages
33
Re: what size motor for my boat?

Had a 12'er with a 9.9 and with one person that thing would haul, did really well with 2 people too.
No sticker as in HP limit or registration numbers?
Where I am if you have any power source other than human it needs registration numbers on it, even a trolling motor.

It has registration numbers on side but no tag that has hp limit.
 

tashasdaddy

Honorary Moderator Emeritus
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Nov 11, 2005
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51,019
Re: what size motor for my boat?

that boat and a 9.9 will make a nice package. it will be a while before you both out grow it, if you like to fish.
 

rndn

Commander
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May 20, 2007
Messages
2,323
Re: what size motor for my boat?

Go with the 9.9 and make sure the user is well trained on boating and has attended a boater safety course.
 

speedfreak07

Recruit
Joined
Apr 21, 2008
Messages
1
I Was Wondering If There Was Any Way Of Getting Anymore Power Out Of My 1990 20 Hp Johnson 2 Stroke. I Was Wondering A 25, 30, Or 35 Hp By A Carb Or Powerhead Change. Or Is There Any Other Way Of Adding Power To This Motor.
 

tashasdaddy

Honorary Moderator Emeritus
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Nov 11, 2005
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51,019
Re: what size motor for my boat?

speedfreak07, start your own thread, in the johnson forum. hijacking is rude. welcome to iboats.
 

Boatist

Rear Admiral
Joined
Apr 22, 2002
Messages
4,552
Re: what size motor for my boat?

I have a 14 foot Klamath with a 15 Hp Johnson. It planes fine with the wife and Me but with 2 buddies and fishing gear will not get up and plane. Also with the wife and 2 kids would not plane. I should note that my 15 HP is a 1975 so rated at the power head not the prop shaft. I do not remember what year they made the change from power head HP to Propshaft HP but I would find out before buying a motor as makes a pretty big difference.

The Johnson 15 is the same weight as the 9.9 motor as the same with the exception of the carburator and Exhaust tuning.

If the 10 MAX is not a requirement on your lakes go with 15HP.
 

marquette

Petty Officer 1st Class
Joined
Apr 18, 2006
Messages
372
Re: what size motor for my boat?

hi
i have a 12ft Sea King boat. mine is about 20 yrs old. it is a very shallow lightweight boat. i can easily load it into the back of a pick up by myself and usually don't take the decoys out. i use a 1976 4hp johnson weedless on it. i have to put the gas tank and everything else in the front when i am by myself to keep the back end from sitting low and the bow waving in the air. with a person in the front it will ride level but not plane. i can't read the CG plate real well but it says either 6 or 8 for the hp rating. a 9.9 on my boat in the hands of a skilled operator and some weight in the front would be a kick to drive but in the hands of a beginner unless you can limit the throttle will be a disaster waiting to happen. and if your son is anything like i was he won't just go half throttle like he was told. my dad started me out on 13ft Peterbourgh cedar strip boat with a 12 Sea King and told me i could only go half throttle when he wasn't in the boat. that lasted until i got around the first corner and out of sight. when it comes to speed and listening i don't think kids have changed much. i have started 2 boys out with my Sea King and 4hp and i am sure that they wanted more power but they still got the fun of being on their own exploring shorelines and islands. i stared both my son and nephew out helping running the boat when they were 6 and when they were 8 if they could prove they could start the motor on their own and dock the boat they could start going out on their own as long as they stayed in sight of the cabin and ALWAYS wore their life jackets. by the time my son got his drivers licence he could arrive at a launch ramp on his own, launch a 17 ft Crestliner and be fishig before most of the adults could figure out which way to turn the wheel to back up a trailer. don't worry about how much horsepower, think more about safe horsepower because to a kid the fun is in the getting to go on their own.
 

scully222

Seaman Apprentice
Joined
May 1, 2007
Messages
33
Re: what size motor for my boat?

Thanks Marquette for the advice. My son will be turning 18 this week. He has driven some but I'll be careful to talk with him and go out together for awhile. I wanted a little more hp so I could get bigger boat if I see one.
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: what size motor for my boat?

I have a 12' aluminum Sea King...very similar to your Sears boat. It's rated for 10hp, also like most of the 12' tinnies.

I have a 6hp Johnson on it, and, with the gas tank and trolling motor battery up front, it planes and does about 15mph.

I'd rather have a 9.9, but my father, bless his heart, gave me this low hours 6hp, and it'll have to do.

Lots of guys around here run 14' aluminum boats with a 9.9, and I envy them zipping around the lake. By that, I mean to say that the 9.9 will do just fine if you move up to a 14 footer.

I wouldn't put a 15 on any 12' Sears aluminum boat I've ever seen. Too darned fast, and the poop can hit the moving blades awfully quickly in a 12' boat. I'm betting that yours is actually rated for 10hp.
 

External Combustion

Chief Petty Officer
Joined
Aug 21, 2007
Messages
608
Re: what size motor for my boat?

My old 14' Appleby (150 lbs) with a Scott 7 1/2 horse will get up on plane with me and my fishing gear. Nothing else on board will allow such speeds.

I have noted though, that with anything over 1 and 1/2 foot waves it is more than a handfull at planing speeds. I always drop back to displacement speed and have a much better time getting back to the ramp.

I think your son will be thrilled with the power of a 9.9 or less. I certianly was and made two trips of over 900 miles one way with an engine that was old and obsolete when I was a pup.

Fishing is about the time spent, less about the fish caught, and even less about the speed getting there. Listen to the yarns of those that have gone before you. Ever hear of them bragging about the speed more than the fish?
 
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