carburetor problems

[Fstued]

Rebuilt my carb on my 1976 A-4 maybe 9 months ago. The engine recently had trouble starting, it won't but prior to that it would run for a few minutes and die Sounded like I was running out of gas. So I finally made the painful decision to pull the carb off and look at it. I wasn't pretty looking. The The bowl had this white gunk on the bottom of it. In general the carb did not look good
Any one have a clue where that stuff came from fuel is my guess but why Do I need to clean and drain the tank. I can't remember if I used gasket sealer I don't think I did. I don't want to do this again.
Thanks

[Administrator]

By chance, did you use any gasket cement or sealant?

Any teflon tape or other sealants at fittings upstream of the carb?

Bill

[JOHN COOKSON]

What a mess. Since everything was OK for ~ 9 months I wonder if you were sold contaminated fuel.
There may be something dissolved in the fuel that can't be filtered out and that something is depositing out in the carburetor. Another possibility is that there is water in the fuel which has dissolved KRAP which is depositing out in the carburetor.
The best I have to offer - and it's not much - is to catch some gas in a clean, dry, clear jar hold it up to the sun to see if there is any KRAP in the fuel. Then let the gas evaporate and look for the goop that is depositing out in the carburetor.

TRUE GRIT

[Al Schober]

You won't know if you have to clean and drain the tank until you know what's in there. There's probably a half gallon or so of stuff down below the reach of the pickup tube, so you have to find a way to take a suction on the very bottom of the tank. On my boat, I can get a 6' length of 3/8 copper tube to the bottom of the tank by going in thru the deck fill - it's almost a straight shot. I connect that tube to a small hand pump and pump into a gallon jug - a clear glass one lets you see what you have.
As for cleaning the carb, good filters changed annually will help avoid the need for carb cleaning. But the unfortunate truth is that alcohol fuels are NOT your friend, and carb cleaning is needed more often than in the days of non-alcohol leaded fuels. Personally, I keep a spare clean carb aboard so I can do the cleaning off-hull. I don't like spilling gas aboard, plus I don't have an air compressor aboard.

[joe_db]

That really looks like something plastic or a sealant/caulk got dissolved in the fuel. The (in)famous alcohol-goo is more like a powder.
IMHO I would examine the entire fuel system including the tank. These filters are not remotely marine-rated, but might be worth temporary use to see what you catch:

[joe_db]

Sort of. One bad side effect of alcohol is the ability to dissolve materials that will then pass through the filter. See Bertram powerboats with slowly dissolving fiberglass fuel tanks that would send resin right through the filters and ruin the engines.

You won't know if you have to clean and drain the tank until you know what's in there. There's probably a half gallon or so of stuff down below the reach of the pickup tube, so you have to find a way to take a suction on the very bottom of the tank. On my boat, I can get a 6' length of 3/8 copper tube to the bottom of the tank by going in thru the deck fill - it's almost a straight shot. I connect that tube to a small hand pump and pump into a gallon jug - a clear glass one lets you see what you have.
As for cleaning the carb, good filters changed annually will help avoid the need for carb cleaning. But the unfortunate truth is that alcohol fuels are NOT your friend, and carb cleaning is needed more often than in the days of non-alcohol leaded fuels. Personally, I keep a spare clean carb aboard so I can do the cleaning off-hull. I don't like spilling gas aboard, plus I don't have an air compressor aboard.

[Fstued]

thanks for all the great replies I will attempt some. Yes I use alcohol fuels, I live in Calif, and using additives, Mystery Oil.
Can the carb be saved is the big question, will a cleaning and rebuild be enough to keep me going? Hope so.
Thanks

[joe_db]

You can always clean it, the question is will it come back?

thanks for all the great replies I will attempt some. Yes I use alcohol fuels, I live in Calif, and using additives, Mystery Oil.
Can the carb be saved is the big question, will a cleaning and rebuild be enough to keep me going? Hope so.
Thanks

[JOHN COOKSON]

Need To Address The Root Cause Also

Can the carb be saved is the big question, will a cleaning and rebuild be enough to keep me going? Hope so.
Thanks

Yes, the carburetor can be cleaned and rebuilt. The problem with this approach it is like treating pain only - it doesn't treat the under lying cause of the pain. Your engine will be unreliable at best. Having doubts when out on the ocean is not a good feeling.

TRUE GRIT

[marthur]

This looks a lot like the semi-dissolved gunk I have taken out of a couple of neglected outboard gas cans. You may wish to take the access plate off your gas tank and visually inspect it just to make sure it is OK.

[Dave Neptune]

Fstued, I'm chiming in a bit late here and here goes. You do not have a carb problem you have a BIG fuel problem that compromised your carb! You WILL need to address the compromised fuel by cleaning the tank, Then install a water separator/filter and an additional "polishing filter" just before the carb and all of this should be on "fresh CG approved" fuel lines. The previous suggestions are excellent. I also strongly suggest a CHEAP fuel pressure gage between the carb and the polishing filter for future ease of diagnosis of issues related to fuel.

Now to the carb itself. With all of the gunk and goo you will need to get after the carb with a good grade cleaner and "hi pressure" air to be sure all of the passages are "clear" with the "metering" parts removed!!! Do be very careful with the float adjustment, make sure the floats are as parallel as possible once the height setting is achieved, I have found it advantageous to set the float a bit "low", about 1/16 of an inch. This I have found to give the idle mix more consistency in the "idle range" and the transfer to the main jet sequence to be far more consistent as far as the mixture is concerned.

Do not try the carb out without addressing your "fuel issue" first. You can use an alternate tank for temporary use to keep things going and remember "fresh fuel lines".

Dave Neptune

[Bratina]

Now to the carb itself. With all of the gunk and goo you will need to get after the carb with a good grade cleaner and "hi pressure" air to be sure all of the passages are "clear" with the "metering" parts removed!!!

Dave Neptune

Great advice from Dave - I'll add to PLEASE wear eye protection when you clean the carb - the cleaner sprays out at high velocity and unexpected angles through the carb. It's harder to sail blind...

[joe_db]

What kind of tank do you have?
On one boat we only could fix the issues by getting an entirely new tank. The old tank was beyond salvage.
If you have a fiberglass tank, you REALLY need to get a new one ASAP.
Also, where do you get your fuel? Remember the *marina tank* is part of the system too if you buy their fuel.

[Fstued]

carburetor gunk

Well I think I found the problem although not sure about solution. While attempting to but everything back together I realized there was water, salt, dripping out of the intake manifold where the carb bolts up to it. So the white gunk must be salt. It is raw water cooled. So I guess maybe I have cracked intake manifold gasket??
anyway the cure to the problem is getting worse. I have rebuilt the carb new filter in the fuel pump new filter between pump and carb and a new gas-water separator but if I have a leak in the cooling system it is going to happen again.
My frustration is great. Thining about a new used engine maybe even a diesel.
Help

[sastanley]

Fstued, Do not panic. manifolds are a few hundred bucks. Check into a diesel conversion (thousands of bucks!!) and we'll move forward. We need to understand why there is saltwater in the manifold. Might need to remove it. It is held on by only three studs.