Smoke and rough idle 4.3 (UPDATE)

True. But the water is held by the ethanol and that is where the corrosion is coming from. The ethanol will trap the water and hold it. And that is one of the reasons it is so bad. It was so bad that I had to buy a used carb to use the both to make one. As for the ethanol being so good for a carb, I disagree to that. Took out three carbs in a Jeep CJ I had and has taken out the carb in an old Jeep XJ I have sitting behind the barn. Same with two lawn mowers sitting out there as well. Not letting them sit is the best cleaning effect on a carb.

And lets not talk about the reduced mileage caused by the use of ethanol. I would prefer to not have it or any type of bio crap in fuels. The disadvantage far outweighs the advantages.
Its proverbial. When the "expert" mechanic can't figure it out, it must be ethanol. Ethanol has been blamed for everything. Its a good scapegoat.

The only valid statement is that it reduces mileage. Do the math. Forget about mileage per gallon. Put your computer to work and calculate Dollars per mile. Non ethanol costs more, but the extra mileage and extra cost does not compute. It's simply not cost effective.

"Water in the gas".....OMG I can't believe you said that. If there is water in it, it is chemically combined and burned right thru. That's an advantage. But where did the water come from in the first place? Either a bad gas station tank, or poor maintenance / storage by the consumer.

Again...in the olden days we DELIBERATELY put ethanol in the tank in the Winter to prevent problems. I guess the youngins don't remember "Dry Gas".....LOL.

Google (remember its your friend) "The myths about ethanol". Good info.

As Scoflaw said, 30 years and no problem. But back then us oldsters knew how to take care of a car (boat, lawnmower, etc). Today, PMs are a thing of the past because there is no time to do anything but follow Farcebook.

Yes, lets not debate. Some of us are boatnuts and others are Saturday night boaters. Neither will ever convince the other. My 40 year old classic Bonneville has been running E10 for 30 years, and had its last carb rebuild 35 years ago. makes you wonder why, doesn't it....
 
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My '97 5.7 gets power with the key in run position. Not sure when that changed but it doesn't have to be running on mine.
I burnt well north of 800 gals of 87 (with ethanol) so far this season in the 245 as well.
 
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Was able to put the boat in the water and test some things out.
Boat fired up perfect without any issues. Choke opened as it should and I was getting voltage to the lead.
I took off the flame arrestor and sprayed into the carb after it warmed up. Seemed to idle a little better. But motor was idleing just fine.
Got the boat on plane and ran it for about 10 mins @ 3000rpm. Brought down to idle, and it sat in neutral at 700rpm with no issues.
Got the boat back on plane, running the rpms a bit higher this time. Maybe 4k max for a short period of time. For another 10 mins. When i brought it back down to neutral, it started hesitating and i saw the white smoke again. I let the motor die and opened up the cover. No smoke inside the bilge. Definitely comming out the back. I removed the flame arrestor and saw this when i did:

Let the boat sit for awhile and had a hard time starting it, but i eventually got it going after a few mins.

Ran a few more times up and down the river, and it never happened again. Everytime i stopped, it purred like a kiten. I would shut off the boat, and it would fire right back up.

I did have the black film on the transom again when i yanked the boat out of the water. Ill upload a picture.

Does the boiling and noise the carb was making after it stalled look normal?
 

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Was able to put the boat in the water and test some things out.
Boat fired up perfect without any issues. Choke opened as it should and I was getting voltage to the lead.
I took off the flame arrestor and sprayed into the carb after it warmed up. Seemed to idle a little better. But motor was idleing just fine.
Got the boat on plane and ran it for about 10 mins @ 3000rpm. Brought down to idle, and it sat in neutral at 700rpm with no issues.
Got the boat back on plane, running the rpms a bit higher this time. Maybe 4k max for a short period of time. For another 10 mins. When i brought it back down to neutral, it started hesitating and i saw the white smoke again. I let the motor die and opened up the cover. No smoke inside the bilge. Definitely comming out the back. I removed the flame arrestor and saw this when i did:

Let the boat sit for awhile and had a hard time starting it, but i eventually got it going after a few mins.

Ran a few more times up and down the river, and it never happened again. Everytime i stopped, it purred like a kiten. I would shut off the boat, and it would fire right back up.

I did have the black film on the transom again when i yanked the boat out of the water. Ill upload a picture.

Does the boiling and noise the carb was making after it stalled look normal?
Id say you have too much fuel pressure or a bad needle and seat or float, fuel bowl is overflowing.

based on previous comments on choke lack of voltage and slow opening that may be separate issue, but both will contribute to rich condition and smoking

check fuel pressure if ok rebuild carb replace float and needle and seat while in there
 
Does the engine have or should it have a carb to intake manifold insulator? What I'm getting at is a possible fuel percolation issue.

:
", fuel bowl is overflowing." Usually if that's the case the long angled trough in the air horn would show fuel running out and into the throat not out of the discharge nozzles.
 
There is a spacer between the carburetor and manifold - about 3/4” on mine. Always been there.
 
Thank you everyone for all the input!!! I havent had any issues since i did a simple carb cleaner spray. But the carb will definitely get rebuilt this winter.
 

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