Water in intake

Twainer

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Carb was acting up so I took it to a guy here in town. Left the boat at the house while we went on vacation. According to my daughter we got a nasty storm the night before we came home. I must have not secured the cover well enough cause half of it was pulled off the boat. Engine compartment was closed but water still got down into & onto the engine. The only thing I had covering the intake was a shop rag to keep dirt & debris out. Obviously it wasn't going to keep water out. I have taken out the spark plugs & blown the cylinders out. Two had some moisture in them. I blew on the intake for over an hour & think I have all of the water out. It is inside at my work now with a fan blowing down the intake tonight to hopefully dry out any moisture I missed. I still do not have the carb back so I couldn't start it if I wanted to. Is there anything else I should do before attempting to start it? Should I spray some fogging oil down the intake before I button it up?
 

strokendiesel002

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Sounds like you've done about everything you can. Check your oil level to ensure that water didn't sneak down past your rings and into the block (if there is water in there, get change oil immediately). If good, fire it up as soon as possible and get it up to operating temp and then change your oil(after shutting off). A little fogging oil shouldn't hurt as long as you don't have any sensors between the point of spray and intake (I haven't seen any yet, bit this is for someone down the road doing a quick search and not noticing you mentioned carb problems).

This is the routine our sleds go through if/when they take a dip
 

alldodge

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Fogging oil won't hurt and can help, but crank the motor over with the plugs out a bit
 

Scott Danforth

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intakes run down hill to the valves

pull the plugs, and turn it over to get any water out (use the starter)

then use liberal ammounts of WD40 down all the intake runners and in each piston

turn it over some more
 

Twainer

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Well... sounds like I am on the right track. After letting it sit all night with the fan on it I was going to do just about everything mentioned above except for liberal amounts a WD-40. It did cross my mind to blow some down the intake but then I got to thinking "doesn't it have some solvent in it?" I know it helps disperse water but I was afraid it might wash the cylinders too much. I will be changing the oil after I run a bit so maybe what little solvent that is in it won't hurt. Thank you much for all of the input!
 

Twainer

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Today I cranked it without the plugs in & got a little more moisture out. Bumped the engine, push compressed air through the intake, then in each cylinder. Did this back & forth for about an hour. Then I proceeded to spray small amounts of fogging oil down the intake & in each cylinder. Used compressed air to force it down in there & then bump the engine & start all over again. Did that cycle four times. Going to let it sit at the warehouse over night with the fan on it again. Tomorrow I will put it back together & wait for my carb to get finished. Once I get it back I will fire it up, get the engine warmed up & change the oil. Then run it some more, check the oil for moisture again. I tell ya if it's not one thing it's another with this old boat! Anybody want to buy a 1978 Mark Twain with almost new everything? :D All joking aside I don't think I am going to keep more than another season or two. The thing is wearing me & the wallet out!:eek: It has a reman engine, top end of the drive was rebuilt before I got, I just had the lower end re built, new floor & carpet, new interior, nice tandom axle trailer, the list goes on & on.
 

Twainer

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Ok so everything has been dried out & put back together. New issue... got the carburetor back & installed but now I am not getting any fuel to it. When I was bumping the engine over with no sparkplugs I was getting all kinds of fuel coming out. Actually had to stuff a 3/8" extension in the hose to keep it from going all over the place. Unscrewed the fuel filter & cup/cover with fuel thinking maybe I need to prime it. Pulled the manual valve off that is right before the filter. It is working properly. While having that off I noticed the fuel tank is full & no fuel is coming out of the tank. Shouldn't I be getting all kinds of fuel pouring out? Manual says there is an anti-siphon valve somewhere. Is that the manual valve I previously mentioned or is there another one in the bottom of the fuel tank? Just for shits & giggles I pushed compressed air down the fuel line & could hear air going into the fuel tank. Am I missing something here?
 

alldodge

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Now that your getting into troubles, we need to know what your working on. V8, V6 other, what motor and drive?

Don't know what the manual valve is but the antisiphon valve is a barbed fitting on top the fuel tank where the rubber fuel line connects to the filter.

Unless the tank is so full of fuel its ready to come out the fill hose, it should not be pouring out the tank with the line disconnected.
 

Twainer

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Now that your getting into troubles, we need to know what your working on. V8, V6 other, what motor and drive?

Don't know what the manual valve is but the antisiphon valve is a barbed fitting on top the fuel tank where the rubber fuel line connects to the filter.

Unless the tank is so full of fuel its ready to come out the fill hose, it should not be pouring out the tank with the line disconnected.

Sorry, it's a 1977 Mark Twain OMC with a 351W. So with the fuel line that is as low as the bottom of the fuel tank, fuel should not be pouring out? Guess that is good for me. I just thought gravity would do it's thing. As I said earlier, I was getting fuel pumping out whenever I would crank the engine over. But got nothing now.
 

Twainer

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Shop manual says to bypass the fuel tank to trouble shoot the anti-siphon valve so I did & dropped the rubber fuel line down into a fuel jug. Still no fuel.
Took off the fuel line directly out of the fuel pump & cranked it over & fuel pumps out. Amount of pressure I don't know but it comes out. Blow down the fuel line from the pump to the carb & it is clear.
 

Twainer

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Yeah I think I will loan out a pressure gauge from an auto parts store to check the pressure. Just weird cause it was pumping fuel everywhere last weekend while I was bumping the engine.
 

Twainer

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If I do indeed need a fuel pump is there a difference in marine & auto? I don't recall if I put a new fuel pump in when this engine was replaced or not. If I did it sure didn't last very long.
 

Lou C

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Probably is a mechanical pump should have the yellow overflow hose fitting from the pump to the carb in case the diaphragm ruptures. The auto version does not have that feature.
 

Twainer

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May 10, 2016
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Starting to sound like a very weak fuel pump

I thought I would test the pump pressure but can't do that since I can't get enough fuel to the carb to run the engine. For some reason I thought I could just crank the engine over & get fuel pressure, but not according to the shop manual. Guess I just need to trust that is what it is & buy a new one.
 

alldodge

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A mechanical fuel pump can suck fuel thru the system without issue. Even an electric can do it. Now if your antisiphon valve is clogged, then neither can do it.

The antisiphon val;ave is on top the tank where the rubber fuel line connectes
 

Twainer

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Really hoping it is not the anti-siphon valve. Tank is full & I would have to take out a bunch of interior parts to get the tank out to where I could work on it. Don't think it is the valve since I put the fuel line into a fuel jug & could get fuel to the carb. Just ordered a pump so I should have it by the end of the week.
 

alldodge

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The valve is not a valve which has a handle or lever on it. Its a barbed fitting with a spring and ball inside it

anti siphon valve.png
 
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