1985 Evinrude 150 Carb Spitting and coughing?

[TearlessTom]

I have been doing all the PM and trying to tune my 1985 Evinrude 150. Last fall I changed the foot oil., Re threaded the drain plug, Replaced the water pump, Lubed everything. I also replaced all hoses, fuel, oil, and vacuum. New plugs and rebuilt all three carbs. Not because it was running bad just because I didn't know when it was done last I also replaced both thermostats.
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Due to work and a sudden illness I have been unable to get the boat out since last summer. I have been released by MD so ready to hit the water.​

My QUESTION IS:​

Engine is V-6 with 3 carbs. Each carb supplies top, middle or bottom two cylinders.
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My #1 cylinder(top starboard) carburetor is spitting fuel out the throat but not the #2(top Port side) which is supplied by the same carburetor. . So much that it starts to run down the front of the carb housing.


The #1 also coughs fairly regularly.


Compression on all cylinders are around 90 lbs. within 5% of each other which seems low but from what I read is pretty normal for this year engine.


Remember the 1st "Gas Crunch" was around 1985 and all gasoline engines were scaled back.
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The other two carbs provide fuel as it should. I rebuilt all three last fall and it hasn't been ran since. I've ordered another rebuild kit but not sure what is causing only one side to be getting too much fuel. I don't want to make the same mistake or overlook something. The carb has set orifices there is no adjustments and has a slow and a fast jet. ​

What could cause this and why only one side.??????

Thanks,
Tom

 

[racerone]

Basically each carburetor bore feeds one cylinder.----Perhaps check the reed valves for #1 cylinder.

 

[TearlessTom]

The reed valve is on the side of the carb under a plate correct? Looks like a fan / comb/ or flat sheet? The fuel is coming out of the base of the vertical copper tube in the center of the throat.

 

[TearlessTom]

Okay been reading up on the reed valve and it does have those symptoms. However my #1 cylinder has the highest compression reading. If it were a bad read shouldn't it be lower than the others?

 

[racerone]

But, but the reed valves have nothing to do with compression in the cylinder !!

 

[racerone]

You might want to look into issues with the nozzle that dips into the carburetor bowl if fuel is ---" coming out the base of the vertical copper tube in the center of the throat "

 

[TearlessTom]

RACERONE: Thanks for your advise and patience. I asked about the compression as I had seen or read that some were while researching the reed valve. It didn't make sense to me but a lot of things don't make sense to me sometimes.

What kind of issues should I be looking for with the nozzle? I assume you are talking about on the underside which would be inside the fuel/float bowl. And are they fixable? is their a "O" ring or something there that I didn't see? What is the name for this part. I couldn't find it on the parts fische.

Inside in the middle of the throat is a very short about 1/4 inch or less in height, larger diameter vertical copper pipe with a longer smaller diameter pipe on the inside of it going the height of the throat. with I assume tiny holes for the fuel to be sucked into the throat as the air comes by that cant be seen from the front. The fuel is leaking from the area where the smaller diameter piece come out of the larger diameter piece.

What are the official names for these pieces so I don't sound so much like a newb...?

Would the float height have any effect on this ?

 

[racerone]

There is only one float for both sides of the carburetor.----You are saying the issues is on just ONE of the nozzles.-----Take carburetor apart for inspection.-----How does this nozzle compare to the other 5 nozzles on the carburetors when engine is running ?------Are the wee screws still in place on the throttle plate for #1 carburetor throat. ?----Note -----you will read lots / see lots on you tube videos that have entertainment value !

 

[TearlessTom]

Yes it is only the nozzle for the #1 cylinder that leaks #2, 3,4,5,&6 all appear the same and you can not see fuel when running/ idling. . # 1 has droplets in the air and leaks bad enough it runs down the outside face of the inside of the airbox . fuel leak gets worse when engine speeds increase.

The two screws on the rod in the center of the throttle plate are both there. I will check for tightness but visually look fine. I don't see any slop of movement in the plate other than the normal rotation with throttle. I assume that is what you mean by "wee screws"

Oh and when engine coughs it is only #1 that coughs.

 

[oldboat1]

Maybe you have an issue with the carb float or the float valve and needle (bowl flooding): http://ww2.iboats.com/Carburetor/dm/cart_id.338508124--session_id.046665865--view_id.1556296

 

[racerone]

One float and one float valve on this 2 barrel carburetor.------And only one side has the issue here.------Take the carburetor off.----Inspect carburetor.----Inspect reed valves for #1 cylinder.