runs good with muffs but in river just dies

ohfishcat

Seaman Apprentice
Joined
Feb 19, 2011
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38
1984 evinrude 50 hp,,,,,,,bought it from a boat mechanic ,after months of bullcrap,,,he put a new starter on it and boiled out carbs,,,,,,ran good first 3 trips out idled kinda low,,,,,,,,,,yesterday we took it down to the river started right up,,,,but then when you push fast idle down it just wants to die out cause it idles too low,,,,,couple times i did get going in gear but when you accelerate,,,,it bogs and dies out,,,,,,,,,,,sooo when we got back home we put muffs on it and it ran fine,,,,,,took back out,,,,,,same thing as before low idle and dies out


called a boat service place here he said it sounds like a impeller,,,,,seems to me like it a idle adjustment problem?????dont understand why it runs good on muffs but not in the river
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Re: runs good with muffs but in river just dies

everything runs good on muffs. there is no load on the engine when on muffs.
 

scipper77

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Sep 30, 2008
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2,106
Re: runs good with muffs but in river just dies

I just had the exact same issue. In my case it was a bad head gasket. Don't get me wrong, there are plenty of other things it could be like carb or fuel pump. Can you do a compression test?
 

ohfishcat

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Feb 19, 2011
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Re: runs good with muffs but in river just dies

i havent done nothing to check anything ,,im kinda a dummy when it comes to a 2 stroke outboard,,,,i know outboards are very frustrating
 

scipper77

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Re: runs good with muffs but in river just dies

The standard answer is to check spark, compression, and fuel. In that order. You can pull the plugs and crank the motor with the wires on the plugs and the plugs touching ground. A spark tester would be better. I would start there.
 

boobie

Supreme Mariner
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Nov 5, 2009
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20,826
Re: runs good with muffs but in river just dies

Grounding out the spark plugs will tell you nothing. You need an open air gap spark tester set at 7/16 ". First off, do a compression test.
 

scipper77

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Re: runs good with muffs but in river just dies

If you have a spark tester (air gap tester) and a compression gauge then you should check those things right off the bat because they are both very easy to check and very important for a running motor.

I apologize for not emphasizing the importance of the gap tester. By jumping a larger gap than the plugs have you are ensuring that you have enough spark to perform under load.
 

Rick.

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Jul 30, 2006
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3,740
Re: runs good with muffs but in river just dies

Good advice above. It could be as simple as opening you slow speed needles a bit more if your engine has them. Best of luck. Rick.
 

ohfishcat

Seaman Apprentice
Joined
Feb 19, 2011
Messages
38
Re: runs good with muffs but in river just dies

i appreciate all the replies

its really weird,,,at home with the muffs it runs fine,,,,starts right up,revs like it should,,goes in gear and runs fine,,,in the river starts fine,,,,just wont idle without dieing out
 

glengold

Petty Officer 1st Class
Joined
Feb 24, 2010
Messages
310
Re: runs good with muffs but in river just dies

Dear Ohfishcat-

As mentioned, on the muffs the motor runs easier because there is no back pressure and load on the engine. Never run over 2000 RPM son the muffs; that is bad.... You can try squeezing the primer bulb while in the river to check for a fuel pump or delivery issue.

On a side note: What is with the ,,,,,,,,? You have a broken keyboard too?

Good luck-
Glen
 

glengold

Petty Officer 1st Class
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Feb 24, 2010
Messages
310
Re: runs good with muffs but in river just dies

What RRMs does it die at? Maybe you need to tighten the throttle cable a little or increase the idle.
 

bonzoscott

Senior Chief Petty Officer
Joined
Jul 26, 2008
Messages
745
Re: runs good with muffs but in river just dies

Just a note: The spark gap tester (air gap tester) - found as Thextron 404 - also under a Balkamp# at Napa. Google Thextron 404 and you could get an idea of how it works.
 
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