I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

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kilroy76

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Jun 8, 2013
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Just purchased this pontoon with a E25ELCEB, seller stated his wife turned off the hose on him and was afraid the impeller was bad. I replaced the impeller and wtr pump and started it up with the aid of starting fluid, ran fair until it warmed up and was backfiring under starter. I pulled starter to side and noticed a fuel line was off at the bottom of intake. Reattatched started fine once again until warmed up then the backfire started again same area but no fuel spraying out now. Pulled my plugs, top one wet, bottom one dry but lot of carbon. Any ideas!
 
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Cofe

Cofe

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

Please never use starting fluid on a two cycle engine. It can destroy the motor in a heart beat. I suggest you get a compression tester and post your findings on the compression readings.
 
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OptsyEagle

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

Could you describe the backfire. Is it the loud backfire one gets when combustion happens within the exhaust or are we perhaps talking about a sort of lean sneeze?
 
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kilroy76

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

OptsyEagle said:
Could you describe the backfire. Is it the loud backfire one gets when combustion happens within the exhaust or are we perhaps talking about a sort of lean sneeze?
Click to expand...

lean sneeze
 
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kilroy76

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

Cofe said:
Please never use starting fluid on a two cycle engine. It can destroy the motor in a heart beat. I suggest you get a compression tester and post your findings on the compression readings.
Click to expand...

compression identical on both cylinders 93psi
 
Cofe

Cofe

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

Compression is good. Adjust the carb low speed adjust needle on top of the carb, 1/8 turn at a time. If you can't get the lean sneeze to go away, then your carb needs removed cleaned and rekitted.
 
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kilroy76

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

Cofe said:
Compression is good. Adjust the carb low speed adjust needle on top of the carb, 1/8 turn at a time. If you can't get the lean sneeze to go away, then your carb needs removed cleaned and rekitted.
Click to expand...

I adjusted the air and it ran smoothly until it warms up, that's when the sneeze starts. I'll rebuild the carb tomorrow and see what happens, thanks
 
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kilroy76

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

kilroy76 said:
I adjusted the air and it ran smoothly until it warms up, that's when the sneeze starts. I'll rebuild the carb tomorrow and see what happens, thanks
Click to expand...

Installed the rebuilt carb, took a while to fire up but once it did run much better, however now it sneezes through the exhaust intermittently. Top spark plug still wet and bottom dry but much carbon. Any suggestions? Points?
 
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Jim311

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

Sneezing = it running lean. Is the carb adjusted properly? Does the fuel ball stay firm? Have you rebuilt or inspected the fuel pump at all?
 
Cofe

Cofe

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

If your motor number you posted is correct, then your motor is a 1989 year. It would have electronic ignition.

If it were me, I would do a decarb.
 
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kilroy76

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

Cofe said:
If your motor number you posted is correct, then your motor is a 1989 year. It would have electronic ignition.

If it were me, I would do a decarb.
Click to expand...

Just got back from our maiden voyage and she ran like a raped ape (pardon the pun) pulled plugs both the same but wet. Yes it's an 89, put 86 on original thread, the fuel pump had a little crap in the screen which is far as I went with it, not sure what a decarb entails. Only problem left is water in the lower unit, slightly milky after 1hr of running, I was told to do a pressure test at 15psi and there were a possibility of 3 different seals the could be the culprit, is that a major overhaul or can the novice w/a manual handle it?
 
Cofe

Cofe

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Re: I've 1cyl fouling out and 1cyl dry but extreemly carboned on my 86 25hp Evinrude

Good to see you got her going. The most common leakage of water into the lower unit is the drain screw gasket. They should be replaced everytime... Yes a novice can do a major overhaul with a genuine OEM manual and patience.
Just a thought...remove your prop, and remove any fishing line wrapped around the prop shaft.
 
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