1994 Evinrude 120 hp won't idle

k9hunter

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engine will not idle. starts easily but will not stay running without throttling up to ~1500 - 2000 rpm. cleaned carbs, found 4 #37 orifices in intermediate ports and 3 #33 &1 #26 in idle ports. i believe the 37 go in idle and 33 in intermediate. switched as such. air screw initial setting @ 2 1/2 turns out. replaced plugs and wires. attempted to check timing. apears to be ~ 8atdc. in water runs ok but does not idle long. at higher rpm planes out but has a slight miss occassionally. compression all within ~20% of each other if i remember at ~ 130 psi.

i am starting to runout of ideas.......any suggestions please and thanks in advance.
 

Daviet

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Re: 1994 Evinrude 120 hp won't idle

Could you post your model number, the one I looked at did not use a #37 at all.
 

k9hunter

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Re: 1994 Evinrude 120 hp won't idle

E120TLERC - i believe, i will have to double check it on the motor tomorrow
 

Daviet

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Re: 1994 Evinrude 120 hp won't idle

Here's the way I see it.
#33-Idle air bleed
#31-intermediate
#76D-High speed
Is this motor new to you, could someone have replaced the jets prior to you owning the motor?
 

k9hunter

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Re: 1994 Evinrude 120 hp won't idle

had it about a yr and a half. motor never had a good idle but was able to run. after sitting for almost a month went to take it out and ran normal for about 100 yrds and just died while on plane. it would start with no problem every time but would not take any throttle. ( increase throttle motor bog out and die). heard about all the ethanol "gumming" up carbs so decided to clean which is when i found the orifices. I am pretty sure someone has changed them as the 4 that were in the intermediate ports were not all the same. from what i can find on evinrude website the 37 should be in idle and 30's should be in intermediate for carb w/ suffix "K". Suffix "C" calls out what you discribe, with what is in carbs i assume (u know what they say about that) they are suffix "K"'s. however engine will still not idle.
 

Daviet

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Re: 1994 Evinrude 120 hp won't idle

I guess the first thing to do is decide if it is a sufx "K" or "C" and then get the proper jets in it. Maybe some one swapped carbs sometime in the past.
 

k9hunter

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Re: 1994 Evinrude 120 hp won't idle

Where might i find an identification mark on the carb to tell the difference? from what i can see, the carb body is a different part # but not sure where it might be located.
 

Daviet

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Re: 1994 Evinrude 120 hp won't idle

By the way I read your model number, it is a suffix "C", the last number in the model number.
 

k9hunter

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Re: 1994 Evinrude 120 hp won't idle

i could go with that, however in the break down for the model number i have, it details carb "K" suffix model or carb "C, E, M, R" suffix model any idea how to be certain?
 

Daviet

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Re: 1994 Evinrude 120 hp won't idle

By quickley looking at the parts breakdown the "K" carb does not use a #29, air silencer sleeve. Maybe that will help. Any numbers on the carb body is most likely a casting number.
 

k9hunter

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Re: 1994 Evinrude 120 hp won't idle

ahhh you are correct. I have the sleeve in my carbs, so it is more then likely a "C". that helps some. However the 3 #33's and 1 #28 orifice's were installed in the idle ports. i understnd they are not all the same, however it was not idleing prior to me switching them the the intermediate ports either. i can open up the 28 to match the 33's but i am still having a hard time thinking it will fix the idle issue.
 

Daviet

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Re: 1994 Evinrude 120 hp won't idle

What about the #37's in the intermediate jets? They should be #31's by the parts breakdown. Maybe a combination of all the wrong jets are causing your problems.
 

k9hunter

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Re: 1994 Evinrude 120 hp won't idle

it is a possibility, and my next steps i will let you know the out come. What are the intermediate jets exactly for? not idle - not WOT?
 

Daviet

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Re: 1994 Evinrude 120 hp won't idle

Older motors had only low and high speed jets. A problem arose on newer motors that when going from idle to high speed the motor would stall or stumble. Another circut is used to transition from low speed to high speed. At least that is the way it was explained to me.
 

k9hunter

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Re: 1994 Evinrude 120 hp won't idle

bored out the #28 jet to match the 33's. the 37's are actaully 31's (looked at them under magnificaton). installed jets and idle still doesnt seem rite. motor warmed up and seemed to idle a little longer, but acted as if carbs are loading up and bogged out and shut off. motor spit and sputtered and black smoke would come out exhaust everytime it would sputter.
 

k9hunter

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Re: 1994 Evinrude 120 hp won't idle

Well must have been a fluke.... Engine started fine as usual, however idle still not there. right now it is actually set kind of high ~12-1500 rpm but would not stay at that range and again spit and sputter until it died. like i mentioned before it appreared the air/fuel mixture might have been too rich as there was black smoke from exhaust when sputtering. I did adjust the air screw slightly (~1/4 - 1/2 out on each carb) still not wanting to stay idle. A friend suggested the power pack, but at $250+... i do not want to just start changing parts.

any suggestions?
 

chuckers

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Re: 1994 Evinrude 120 hp won't idle

I have the same exact motor, model no. and I,ve changed the power pack, cleaned carbs twice, changed fuel sources twice, tried to obtain recircultion routing, and vent hose routing, but keep getting the same diagram.!I disconnected the vro, ran mixed gas a little lean, but still won't idle and smokes like crazy. cleaned recir valves faithfully, and blew out all hoses, and still... won't run over 10 seconds.The kicker is, I'm a boat repair man with his own business, in ft worth, for 25 years, and the J/E motors from about 86 up are all the same. Cast iron bemoths that won't stay running, and carbon up extremely bad all the time. Bout ready to throw in the towel on this one, but will follow your thread for a while to see if you come up with any new thoughts. thanks from a guy named chuck
 
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