1993 Evinrude 9.9hp won't idle

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Coldwaterangler

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Hello. I recently purchased a 1993 Evinrude 9.9hp tiller engine that has difficulties idling. I completely disassembled the carburator and cleaned out the bowl as well as the intake ports but it didn't seem to help. Everytime I start the engine, a large cloud of smoke comes out (the engine revs up) and I also notice an oily substance coming out of the exhaust and down by the prop (not lower unit oil). I can keep the motor running if the motor is slightly throttled but as soon as I go down to idle speed the motor winds down and eventually stalls. I feel like the motor is running too rich but I am not sure. I have a fishing trip coming up so I don't have time to order the manual. If someone could help me out that would be great!
Thanks.
 
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Will Bark

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Re: 1993 Evinrude 9.9hp won't idle

Try lightly seat your low speed idle needle and then backing out no more than 1&1/2 turns sounds like you may have the needle too far out and it's too rich. Oily mixture is unburned oil and fuel and is not a problem. You did remove the welch plug on the carb and clean out the idle curicuit holes there; if not then you may be stopped up there. Hope this helps.
 
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Coldwaterangler

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Re: 1993 Evinrude 9.9hp won't idle

Thanks for the info. Sorry for my ignorance but which one is my low speed idle needle? Is it the screw in the top plastic housing with a spring on it? Also, not sure which part is the welch plug and idle circuit holes on the carburator. Thanks again.
 
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Coldwaterangler

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Re: 1993 Evinrude 9.9hp won't idle

Ok. So I tried adjusting the low speed idle needle with no improvement. I tried multiple different adjustments with no luck. Is there anything else on the carburetor that needs to be adjusted? Any other thoughts?
 
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Daviet

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Re: 1993 Evinrude 9.9hp won't idle

Without a tach you really don't know what you idle RPM is, maybe it is set to low.
Maybe set the idle up a little.
When you move the low speed jet, does it make any difference in the idle RPM?
 
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Coldwaterangler

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Re: 1993 Evinrude 9.9hp won't idle

When I adjust the low speed needle, there is no difference in the idle speed. The only way the motor will keep running is if I keep it throttled with the tiller handle. As soon as I let it slow down it kills before it can idle. Sounds like it is bogging down. Not sure what that means. Does anyone know if there is a piece on the tiller handle that needs adjusted? I was just reading something about that tonight. Thanks again.
 
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Daviet

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Re: 1993 Evinrude 9.9hp won't idle

If the RPM doesn't change when you turn the low speed adjuster in and out, you have a problem in the low speed circut of the carb. Thats why you have an adjustmust screw, to control the low speed circut.
 
T

the machinist

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Re: 1993 Evinrude 9.9hp won't idle

On that motor the "Go To" idle jet setting is about 4 threads backed out from lightly bottomed out as these threads are real fine as compared to the courser threads of the older carburetors.

If per chance when you rebuilt the carburetor, did the gasket between the carb & manifold get torn allowing it to now suck air?
 
M

Monte1961

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Re: 1993 Evinrude 9.9hp won't idle

Coldwaterangler said:
Anyone?
Click to expand...

I will have to agree with the earlier posts. I don't know if you missed something during overhaul or if there might have been missing Pryor? Have you tried to do a link and sync? I would suggest investigating carb issue/s, then link & sync.
 
bluemonster1

bluemonster1

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Apr 17, 2011
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Re: 1993 Evinrude 9.9hp won't idle

sounds like the same symptoms my 7.5 merc had..I replaced the stator and she now idle's fine.Also did a link and sync myself prior and no difference,the stator just wasn't putting out
 
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