86 Evinrude 90 hp running hard with cover on

gfuller40

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Feb 10, 2010
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90hp VRO (disabled) starts and runs decent with cover off, sounds like it's running a little rich, shutters at low speeds, takes a bit to reach full speed at wot, but once it is there it runs awesome and smooth. When the cover is on, it idles right down and usually stalls when putting it into gear. My fear is that this is a leak in the exhaust gasket. I pulled the plugs, very wet and dark, Plugs on right too cylinders are a bit darker than the two left. I'm to the point where I need to either have someone look at this, most likely for at least $500 or just junk it and get a new engine... This has been extremely frustrating.


Thanks guys
 

SparkieBoat

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Re: 86 Evinrude 90 hp running hard with cover on

make sure that your cowl latch is not pressing your coil..I had some coils put on backwards once and the cowl latch was pressing the coil inbetween the body and the spark plug wire connection..I think the coils should be facing outward on that motor. It was the bottom left coil that was my problem.
 

gfuller40

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Re: 86 Evinrude 90 hp running hard with cover on

I don't believe it is... Although, it's always a pain to get on because the spark plug wires get caught in the latches.... The engine still runs like crap with the cover off, just worse when it's on ;)

Another thing i noticed when taking off the airbox cover is that there was liquid in there, appeared to be fuel, not a ton, but a couple teaspoons at least.

Gas leaks out of Carb when primed hard as well....
 

SparkieBoat

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Re: 86 Evinrude 90 hp running hard with cover on

you have a stuck needle valve my friend...time for a carb rebuild. still make sure the cowl did not crack/break any plug wires or coils.
 

gfuller40

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Re: 86 Evinrude 90 hp running hard with cover on

Well i guess it could be worse.... Should i get the rebuild kit from evinrude, or just try and clean what I have?
 

SparkieBoat

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Re: 86 Evinrude 90 hp running hard with cover on

you can try to clean it..but a rebuild kit is cheap, get 2 and do both carbs, specially if its been a while. also water pump impeller needs changing every couple of years or so...and gear case oil.
 

gfuller40

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Re: 86 Evinrude 90 hp running hard with cover on

You got it - I'll let you know how i make out!
 

gfuller40

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Re: 86 Evinrude 90 hp running hard with cover on

Okay - I think i've resolved this one. Rebuilt the carbs - no more leaking of fuel when I use the primer bulb - Checked the Primer Solenoid, when squeezing the fuel bulb, fuel was gushing out the little hoses that bypass the carbs, this happened regardless of what position the little red lever was in, clearly this should not be happening - lastly, there were two bolts missing in out of the exhaust manifold, thus leaking exhaust under the cowl, making the engine run like crap with it on... Haven't tested yet, but will post the results!
 
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