Manafactures motor size recommendations.

[The Quadfather]

So here is my question..... on my 14 ft. Lund I think the specs. are something like.... 4 peeps or 660 lbs whichever comes first.
They say the boat can handle up to a 25 hp motor. Is that motor based on if the boat was full? or not.
Also, what do you all feel about their figure on the motor. The other day I saw a Merc. 15 hp, and thought it looked kind of big at a 15. I mean if they say 25 hp, I guess that is fine........... right?
Also, do I need a long shaft or short shaft?
I know Sam Kalefish has pushed going to 20/25 but I wanted to hear from others.

Thanks

[fish4brains]

My duck boat is a 14' lund flat with a 25hp and it moves out, enables me to sleep longer on hunting days(hehehe). The specs that they give mean that the vessel can legaly only have a motor up to 25hp. Any bigger and you can get a ticket and be required to remove motor. In my opinion I would pust as big a motor as you can afford and as recommended my spec tag. It sucks to spend money on a smaller motor and then wish you went bigger, reserve throttle is always better. Go big or go home!! For that boat a short shaft should do but your boat motor dealer will know.

[hewesfisher]

I'm with fish4brains, get the most motor you can afford and legally hang off your transom. There won't be much weight difference between the 15 and 25 anyway, nor will there be much size difference either.

Your boat tag tells you max motor and max weight capacity, they are not dependant on one another. If you put a lightweight 10hp on your boat you still can't exceed the boat's rated capacity at 660lbs and/or 4 persons, so it doesn't matter if you choose a bigger motor. Keep in mind one thing, USCG certification plate ratings are based on adults weighing 150lbs/each. So, if you have some "heavier dudes" (as Crocodile Dundee would say) on board, be smart and take that into consideration. I know many boat manufacturers have been lobbying to get the USCG to change the weight classificiation to a more realistic level.

When I still had my 14' Hewescraft, I always wished I had a 25hp motor so I could get on plane a little faster and have some reserve power. The 15hp 2-stroke Merc was a great motor, but just a tad slow out of the hole. Once on plane and trimmed out, it would do 23 - 25mph at WOT which wasn't shabby. BTW, I always ran it at WOT unless I was in a speed limited zone or coming into a fishing hole.

On my new Hewescraft I went with max allowable HP and don't regret that at all. I rarely run more than 4200 - 4400rpm (that's about 33mph) and can run for hours like that. If I open it up, I can hit 45 - 46mph but what's the need? We only burned 13 gals in 3 days at Lake Roosevelt inlcuding a bucket load of trolling time. I personally believe you get better fuel economy with a larger motor since you don't have to run it as hard as a smaller one.

Shaft length is dependant on transom depth. Measure from the top of your transom to the bottom of your hull, it will either be 15" or 20". That's what determines which shaft length motor you buy.

[Bodofish]

Dead on. On that note, I think were going to see the transoms get taller or the max hp go down in the near future. The newer four strokes out weigh their two stroke counter parts. The CG figures the max hp by the average weight of the OB and that mythical 150# dude sitting on the back seat. Then there's the drop tests and how hard do I have to pull to rip the transom out. Most comes from OB and dude weight combined. I've never had any trouble keeping under the max occupancy, It's the weight you need to keep an eye on.

[Easy Limits]

I had a 14' Northwood (same hull as a Smokercraft) that had 30 HP max rating. I had a 15HP Yamaha four stroke on it. The boat ran great with just me in it. But when there were two guys in the boat the boat speed dropped in half. I wished I had bought a 25 HP motor for it.

My new 16' Alumaweld has a 60 HP max rating and I got a 50 HP four stroke for it. I am glad I did considering they were selling the boat as a package deal with a 40 HP two stroke.

Get as much horsepower as the boat will take! You won't be sorry.

[needabiggerboat]

Ok my boat is a 1964 glaspar tacoma 16' fiberglass deep-v.
The big motor it came with is 1978 evinrude 35hp 2 stroke.
The boat is rated up to 90hp.
Now the fun stuff I am a mechanic for a living and all the tuning and tweeking in the world won't change the fact that she is way under power. I purchaced a fancy hydrophoil from auburn sports in another attempt to make an improvement. small change but still under power.
The stuff I have read from boating tech books is that the boat requires 35% min of the hp rating to even opperate at min performance under unloaded (weight) conditions.
The bottom line is to go with the max available hp for your boat or you will definetly tell the differance.
But never forget that money is the true factor otherwise I would have a brand new 90hp honda 4stroke on my old crusty fishing machine. Sorry I love the old school boats.

[justinc210]

Yes, Honda Four's are very expensive. The last time I checked on one for my 10' Livingston a 9.9 HP ran at about $4000 brand new. Not exactly in a College student's price range. However, a cheaper option does exist. I found out about the Tohatsu brand (the same company that makes engines for Nissan) recently and they sell a 9.8 HP for $1600. To make the deal even better their engines are lighter than Honda's engines and all share the same great fuel economy and emissions standards. I made a quick look on the web and it seems that the savings continue throughout their line of engines, not just the smaller models.

[Bodofish]

Can't go wrong with those Tohatsu's. They make the power heads for most of the big guy's (yam, merc, nissan...) except Honda. I have a Merc 9.9 and it's with out a doubt the best kicker I've ever owned. The best part about it is all the controls are in the twist grip tiller. took a bit to get used to it but I'd never go back.

[jmay]

I have sent my whole life using and working on outboards. I am a boat/yacht claims adjuster, and was a certified Merc outboard tech, and turn wrenchs to pay for college.

I am a Merc guy, period I think the best engine ever made in a Merc inline 6.

When I bought my last outboard last year I bought a Merc right?....Wrong I paid $500 less for a Tohatsu.

Tohatsu has been making all the Merc 4 stokes, the only differance is the shift lever and the color of the cowling. That said I am so happy with my 9.8 4stroke. I starts everytime, I have changed the lower unit oil twice and the crack case oil 4 times and the oil is as clean coming out used as the new oil. They build a wonderful engine.

Always buy the biggest engine that your boat will take. Outboards are like pistol's better to have it and not need it than need it and not have it.

[TroutCowboy]

OK, this is slightly off-topic, but the other day I was looking for a chart to help me decide what size electric trolling motor to buy for my boat. I found this article, which was helpful (if not frightening -- I'm going to need a 74lb thrust motor, a bank of batteries and a 2nd job to pay for it!).

BASSPRO.COM: Choosing an electric trolling motor

[CraigVM62]

I have sent my whole life using and working on outboards. I am a boat/yacht claims adjuster, and was a certified Merc outboard tech, and turn wrenchs to pay for college.

I know this is going to be the dumbest question you have ever been asked but you sound very qualified so I thought to ask....

I see how electric motors are not rated so much by their motor amperage draw or size ... but by the amount of thrust they provide. Have gas motors ever been rated in lbs of thrust ???