need help choosing a motor for my boat, please help!

loganneet

Cadet
Joined
Mar 19, 2007
Messages
17
hey, i need some help, i have a small 8 foot long by 4 wide fiberglass speed boat that i picked up from a friend its a verry shallow v almost flat bottom in the rear, it was a hull when i got it and was originally a jet boat, although it was missing the motor and jet, so i converted it to outbard power. i picked up a sears gamefisher 5 horse at a yard sale for $60 thinking that it would at least get it on plane because the boat with me in it weighs only about 250lbs, but the motor wouldent get the boat on plane it came close but nope. so i need a motor that dosent weight much more than what i have but has plenty of power to get the boat on plane, and is readily avalible used does anyone have any sugestions? thanks
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,753
Re: need help choosing a motor for my boat, please help!

If you are considering a 9.9, you might as well jump up to a 15 hp Johnson or Evinrude.
Weighs the same as a 9.9 hp, 86 pounds.
There's a million of them out there.

Sounds like a cool little boat. Got any photos?
 

tashasdaddy

Honorary Moderator Emeritus
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Nov 11, 2005
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51,019
Re: need help choosing a motor for my boat, please help!

pictures!!! you will get better help, also the corrent length shaft if important.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: need help choosing a motor for my boat, please help!

The Gamefisher was probably a poor choice but if you play with the set up you may be able to get it to plane.Raise the motor vertically until just before ventilation becomes a problem.A tiller extension may help get the weight forward so it will plane.Also carefull adjustment of the motor trim.we used to easily plane a 12 ft steel boat with a 180lb
adult with a tiller extension on a 5 hp Gale (like Evinrude).Also planed with a 140 adult and 2 50lb kids.I mean planed easily in about 50ft.
A 5 hp Evinrude will have more kick than the Gamefisher a 7.5 will fly and a 9.9 or 15 may be a little scary.
 

jauguston

Petty Officer 2nd Class
Joined
Mar 10, 2007
Messages
104
Re: need help choosing a motor for my boat, please help!

I'm no expert but a mid-80's Evinrude 7.5 or 8 hp (I have a 8) weights 56# and would seem like a good choice. Engine weight on that small a boat would be a issue.

Jim
 

loganneet

Cadet
Joined
Mar 19, 2007
Messages
17
Re: need help choosing a motor for my boat, please help!

thanks guys, il try to get the pics later when i get home, yeah i think the weights gonna be a big issue but you should be able to tell by the pics
 

loganneet

Cadet
Joined
Mar 19, 2007
Messages
17
Re: need help choosing a motor for my boat, please help!

heres the pics. i saw that thoes game fishers are bringing good money on ebay, and i also have an old 1940 evinrude sportsman, i think i will sell both to buy a new motor. so everybody thinks i should get a 10-15hp evinrude for it? thats not too heavy? the motor i have sits it down in the back pretty far.
 

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kenmyfam

Supreme Mariner
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Aug 10, 2006
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14,392
Re: need help choosing a motor for my boat, please help!

Looks like that motor needs to go up by about a foot !!!! Cavitation plate should be about 1 inch above bottom of hull. Play around with the trim as well to get optimum performance.
Should probably plane out for you then if you were close before.
 

loganneet

Cadet
Joined
Mar 19, 2007
Messages
17
Re: need help choosing a motor for my boat, please help!

so i need to raise the angle of the motor so its more hrizontal instead of vertical? whats the Cavitation plate sorry im new to this, i was told that changing to prop would make a big difference also, is this true and if so are props expensive? i would still like to know, wheather or not a 15 or 10 hp would be too heavy for the boat.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: need help choosing a motor for my boat, please help!

you need to put a jack plate on it, and raise the motor straight up. the cavitation plate is actually, the anti cav. plate, is the flat fin just above the prop. if you put a strait edge on the keel of the boat and extend it out, the plate should be above the straight edge, and horizonal to it. tilting will only cause the stern to do down and the bow to come up. what we are saying is there is too much motor in the water. i would say 15 would be top. by the way nice little boat.
 

studlymandingo

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Joined
Mar 22, 2006
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2,716
Re: need help choosing a motor for my boat, please help!

what we are saying is there is too much motor in the water.


WAAAY too much motor in the water. You will have to make some kind of bracket to mount that motor on that raises it up considerably. It will make a HUGE difference.​
 

loganneet

Cadet
Joined
Mar 19, 2007
Messages
17
Re: need help choosing a motor for my boat, please help!

great! thanks alot! i get it now lol, i should be able to build some sort of bracket to raise it, and we will see what kind of difference that will make, if its still not fast enough i think il go with a 10 or 15 hp. so what about the prop? would changing the prop make a big difference?

by the way, that boat was given to me it was a jet boat, have4 you ever seen anything like it? i cant find a single one like it anywhere, its a little rough right now, i have the chrome that goes around the side, and some, new red paint for it, i put all new wood on the inside because the original floors were almost gone, the boat sat for years but seems to be in excelent shape, i live in clarkston washington by lewiston idaho, the get boat capital of the world, and i was told that it might have been made locally by a company called glass cat but i dont know
 
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