evinrude 55hp overheating

massvike34

Recruit
Joined
Dec 1, 2012
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4
So i have a 1976 evinrude 55 hp outboard that runs fine and pee's water consistently, except when at full throttle.
When at full throttle, after about 30 seconds to a minute the overheating alarm goes off. One of my friends noticed the stream coming out the cooling system was not as strong when at full throttle so i had him look back at the prop area and we are all convinced the intake holes aren't being fully submerged in water. is there ANY way to correct this? The engine is moved down the the lowest possible setting on the boat (1989 16 foot maxum bowrider, dont know if that helps), but is there any way to get more water to the intake holes to prevent the motor from overheating? let me know with any possible suggestions anyone. it sucks having to keep it slow all the time.
 

schematic

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Jan 12, 2008
Messages
1,102
Re: evinrude 55hp overheating

Did it ever function properly? Is this a recent install? Is this a short shaft engine on a long shaft boat?
 

massvike34

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Joined
Dec 1, 2012
Messages
4
Re: evinrude 55hp overheating

just bought it in December, never ran at full throttle without overheating the many times ive take in out though
 

schematic

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Jan 12, 2008
Messages
1,102
Re: evinrude 55hp overheating

the anti cavitation plate should be near parallel to the bottom of the boat. If its 6-7" above......its the wrong leg length for the boat
 

massvike34

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Dec 1, 2012
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Re: evinrude 55hp overheating

nope just checked, the anti cavitation plate is almost directly paralell to the bottom, however, there is a small plastic sensor like piece of plastic coming down right behind there, i dont need the piece since it doesnt go to the speedometer i actually use so could it be restricting waterflow to the intake?
 

itsaboattime

Senior Chief Petty Officer
Joined
Jul 4, 2007
Messages
791
Re: evinrude 55hp overheating

Yeah, I agree with schematic. It may be worn to the point that it is slipping at higher RPM.
 

massvike34

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Joined
Dec 1, 2012
Messages
4
Re: evinrude 55hp overheating

ok will do, although i just had the impeller and such replaced, it was done by a marina i had past issues with, so that may be the case
 
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