Outboard is washing out the water and going nowhere?

geckogeek

Seaman Apprentice
Joined
Apr 3, 2007
Messages
32
The 50hp merc mounted on my 14' runabout "washes" all the water away from the prop anywhere above 10mph and revs out. I can't even get the boat on a plane before I have to let off........I don't understand. I tried every stop position(trim) and nothing helps. Why would this do that and how do I fix it?

Thanks
 

bassboy1

Lieutenant Commander
Joined
Jun 23, 2006
Messages
1,884
Re: Outboard is washing out the water and going nowhere?

Is the boat a long shaft and the motor a short shaft? measure from the top of the transom, at the area that the motor sits (some have drop downs for the motor) and measure to the lowest point of the hull. If it is about 15 inches, short shaft. About 20 is a long shaft. Now, measure from the top of the transom clamp. (Where it makes contact with the top edge of the transom.) and measure to the cavitation plate. If 15, short shaft, and 20 long shaft.
If they match, then I don't know.
 

deejaycee_2000

Captain
Joined
Mar 28, 2006
Messages
3,447
Re: Outboard is washing out the water and going nowhere?

take a pic of your motor on your boat setup so we can have a better understanding ........
 

tashasdaddy

Honorary Moderator Emeritus
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Nov 11, 2005
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51,019
Re: Outboard is washing out the water and going nowhere?

sounds like BB1 is right on this one.
 

geckogeek

Seaman Apprentice
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Apr 3, 2007
Messages
32
Re: Outboard is washing out the water and going nowhere?

What is the cavitation plate? Boat is long shaft for sure. Thanks
 

Reel Poor

Vice Admiral
Joined
Jan 29, 2005
Messages
5,522
Re: Outboard is washing out the water and going nowhere?

Here is a simple diagram.

shaft_length_small.gif
 

geckogeek

Seaman Apprentice
Joined
Apr 3, 2007
Messages
32
Re: Outboard is washing out the water and going nowhere?

Ok great diagram. Transom height is 21" Shaft length is 17.5".....now what....I just ordered $300 worth of parts from Oldmercs.com. I might beable to cut and reinforce the top of the transom to lower about 2"
 

studlymandingo

Commander
Joined
Mar 22, 2006
Messages
2,716
Re: Outboard is washing out the water and going nowhere?

Is it possible you have a spun hub on your prop?​
 

geckogeek

Seaman Apprentice
Joined
Apr 3, 2007
Messages
32
Re: Outboard is washing out the water and going nowhere?

Never thought of that.....is it on a key or something? I should maybe lower it the 2" anyways. I can do it nicely if I take the aluminum trim off and refit it.

Thanks
 

tmcalavy

Rear Admiral
Joined
Aug 29, 2001
Messages
4,005
Re: Outboard is washing out the water and going nowhere?

Or you could look for a jackplate to fit your transom, that puts the motor out away from the transom and higher or lower as you desire/need. That way you wouldn't have to butcher the transom just to accomodate the Merc you have now. Check the boat shacks around where you live and Schmebay.
 

geckogeek

Seaman Apprentice
Joined
Apr 3, 2007
Messages
32
Re: Outboard is washing out the water and going nowhere?

Hey that is awesome....I didn't know such a product existed Thanks Again
 

studlymandingo

Commander
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Mar 22, 2006
Messages
2,716
Re: Outboard is washing out the water and going nowhere?

The prop is mounted on a shaft that is in a rubber bushing, the bushing is attached to the inside of the prop. It is designed to spin if the prop strikes something. However, it is rubber and rubber dry-rots, sometimes they just spin out. When this happens, the motor will rev to the sky but the boat will barely move.​
 

geckogeek

Seaman Apprentice
Joined
Apr 3, 2007
Messages
32
Re: Outboard is washing out the water and going nowhere?

I will check the hub next week when my bottom end seal kit and impeller kit shows up......Thanks for the help....I'll let you know
 
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