87' Evinrude Choke Problem (carb trouble) 15hp

danbiggs

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Jun 21, 2012
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I have a 87 evinrude 15hp that I had not run in 2 yrs.. I bought this outboard new. Took it out today did not have much problem starting it. Fresh gas, cleaned the plugs and it fired up. The problem is it will not stay running unless choke pulled out or closed. As soon as I push choke in or start to open motor dies. Pulled plugs and they were right wet. I'm thinking that something in carb stuck. Motor 25 yrs. old carb never rebuilt. Thanks for any suggestions.
 

5150abf

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Aug 12, 2007
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5,808
Re: 87' Evinrude Choke Problem (carb trouble) 15hp

Welcome to iboats.

Start from the start, you will need a spark checker and a compression gauge, you can get both at any auto parts store for under $30.

Check your compression and spark and make sure you have both, compression should be within 10% on both cylinders, generally anything 90 + is good depending on the engine.

If you have spark, it should jump a 7/16 open air gap on the tester, and compression is good it is a dirty carb.

You need to actually dissasemble and physically clean the jets, there are no soaks or sprays that will get it done right, I am not familiar with your engine but there should be 2 jets on top of the carb and one in the bottom of the float bowl behind the drain screw, those need to be removed and cleaned by running a wire through them.

If tyhis is your first time do one jet at a time and replace it then move to the next, and if you have to turn any adjustment be sure to count and WRITE DOWN how many turns to bottom.
 

danbiggs

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Jun 21, 2012
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Re: 87' Evinrude Choke Problem (carb trouble) 15hp

#1 cylinder 122, #2 cylinder 120, spark 7/16". So now the carb is lying on my work bench waiting for me and the rebuild kit I got today. Will start on it as soon as I get home from from fishing. Had to slip my 87' 25hp Evinrude on the boat this evening. Thanks for the reply will let you know how it turns out.
 

Daviet

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Sep 24, 2008
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8,958
Re: 87' Evinrude Choke Problem (carb trouble) 15hp

If you have the early production carb with the core plug on top, make sure you remove the core plug and clean the tiny passages in there, they are part of the idle circut.
 

Rick.

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Jul 30, 2006
Messages
3,740
Re: 87' Evinrude Choke Problem (carb trouble) 15hp

That is terrific compression IMO. Good advice above. I would only add to use lots of compressed air to blow out the passages after the carb cleaner. Best of luck. Rick.
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,471
Re: 87' Evinrude Choke Problem (carb trouble) 15hp

I use canned 'duster' air w/a straw to blow out/check passages when cleaning carbs. Quite handy if you don't have an air compressor near your bench.
 

danbiggs

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Jun 21, 2012
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Re: 87' Evinrude Choke Problem (carb trouble) 15hp

Well first want to thank all the people that reply. Got home Sat. and the 25hp had given me some trouble on the water. Turned out I had to keep pumping bulb to get back to landing. But was a quick fix changed end on fuel line at motor which had air leak thus not picking fuel up. Ran great today! Cleaned and rebuilt carb on 15hp and it runs like new. The bowl had had water in it from stain that was on float and what looked like dried river water in bowl. The most noticeable fitting was the pick up in bowl, pretty bad. Thanks again!!!
 
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