Evinrude 8 horse loses power

ba_50

Chief Petty Officer
Joined
Apr 4, 2001
Messages
635
We have a 1985 8 hp Evinrude that acts up once in awhile. I would be going around 15 mph when the normal engine sound changes to a wah-wah-wah type sound and the speed drops to around 3-5 mph while the engine is still wound up. If I run it at a low power setting for 3-5 minutes, it goes back to normal. The outside temp was around 80 degrees. There is no thermostat in the motor and it has new plugs which did help. I emptied out the gas can and put new gas/oil in it. The water pump it putting out water OK. <br />I felt the head once and it wasn't hot. It has done this 5-6 times.<br /><br />Does anyone have any ideas? Thanks.<br /><br />Bob.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Evinrude 8 horse loses power

You may have a bit of debris in the float bowl on the carb, or you may have a failing fuel pump that can't keep up with the fuel usage at high power settings. They are worth checking.<br /><br />Good luck.
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<br />JB
 

scupbarron

Recruit
Joined
Mar 12, 2001
Messages
3
Re: Evinrude 8 horse loses power

check your prop spun propeller hub a possibility ...if engine is still turning up RPM,s and your going nowhere this could be it
 

kalloway

Seaman Apprentice
Joined
Dec 10, 2000
Messages
31
Re: Evinrude 8 horse loses power

It is not clear if you are maintaining RPM when you say the motor is still wound up, I imagine you mean throttle is still open. <br /><br /> Check for water in your gas. If you can get the cowling off the motor easily and put your hand over the carb opening, choking it, or just pulll the choke out a little at a time and see if it picks up. If it does pickup, you know it is the carb related, either blockage or water.
 

ba_50

Chief Petty Officer
Joined
Apr 4, 2001
Messages
635
Re: Evinrude 8 horse loses power

Kalloway,<br /><br />I did state that I cleaned out the can and put fresh oil/gas in. As far as the RPM I couldn't teel if it was the same as the tone and variation made it difficult to tell but I would guess it wasn't as many rpm. The carb had about 10 gallons of gas run through it so I doubt if it was dirt breaking loose. <br /><br />The fuel pump and prop check sound like good ideas. It will be awhile before I can do anything as it is in Florida and I'm in Illinois right now.<br /><br />Thanks for all the ideas so far.
 

Bryon

Recruit
Joined
Apr 8, 2001
Messages
1
Re: Evinrude 8 horse loses power

I had the same problem with my chrysler 20hp. Turned out the vent on my gas cap was not opening and it was creating a vaccuum. Run your engine until it starts "dogging" and open the cap to the gas tank and see if it makes a difference... Good Luck!!!
 
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