90 HP Evinrude surges at higher RPM's

Blue Bandit

Recruit
Joined
Jun 14, 2012
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4
I have a 1993 Sea Nymph with a 90HP Evinrude outboard. The boat runs good at low to medium RPMs but when you get up to about 4500 RPM or above it boggs down and then back to speed then boggs down and back up again. It continues to do this. Also after everytime you shut the engine off you have to choke it for it to start. Once started it will stay running. Any help would be greatly appreciated. Thank you
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 90 HP Evinrude surges at higher RPM's

Try constantly pumping the primer bulb and see if it corrects the problem, if so it could be a defective fuel pump.
 

Blue Bandit

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Jun 14, 2012
Messages
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Re: 90 HP Evinrude surges at higher RPM's

Would this fix the problem of having to choke it in order for it to start also?
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 90 HP Evinrude surges at higher RPM's

How long do you leave it sit before you have to choke to restart ??
 

Blue Bandit

Recruit
Joined
Jun 14, 2012
Messages
4
Re: 90 HP Evinrude surges at higher RPM's

Short periods of time. Just long enough to get a tuber in the boat. Or long enough to park at the dock to get the truck and trailer.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 90 HP Evinrude surges at higher RPM's

Sounds like it's carb job time.
 
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