Could water in the gas tank cause this problem?

pensacola

Petty Officer 2nd Class
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Feb 24, 2008
Messages
137
I am still having a problem with my mercruiser 305. It will run at 10 mph all day long. But I can give it more throttle and it will either choke out or stay at the same rpm with the stick all the way down.
I pulled the fuel water separator and dumped it into a glass. It was clean fuel until the last bit came out it was some rust colored water. The filter is only about 2 months old. I went ahead and replaced that but still no fix. We opened up the carb and you could see little water molecules sitting on the jets and such.

But my question is if there is water in the tank why would it run at 10 mph steady all day? I would think if there was water in the gas it wouldn't run right at all. It will rev up to 5000 rpm's if I do it slowly. But if I try and rev it quick it pops in the carb.
Any help is much appreciated.
 

Don S

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Aug 31, 2004
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62,321
Re: Could water in the gas tank cause this problem?

Anything is possible. Do some checking.
 

pensacola

Petty Officer 2nd Class
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Feb 24, 2008
Messages
137
Re: Could water in the gas tank cause this problem?

First we are gonna try taking the fuel line loose from the tank. Then run it directly to a new tank and see if that helps. If so then we can either rule out the tank or we know its something in there.
 

Coors

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Dec 8, 2006
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3,367
Re: Could water in the gas tank cause this problem?

Water still in the carb bowl?
 

Bondo

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Apr 17, 2002
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71,148
Re: Could water in the gas tank cause this problem?

Ayuh,....

Fixing the sourse of the water is Great,..
But,...
The Carb will need rebuilding as Well, before your troubles go Away....
 

pensacola

Petty Officer 2nd Class
Joined
Feb 24, 2008
Messages
137
Re: Could water in the gas tank cause this problem?

Definetely. My mechanic has already pulled the carb and is rebuilding it as we speak. I beleive the only way there could be water in the top of the carb is from the tank. How else could it get there?
 

pensacola

Petty Officer 2nd Class
Joined
Feb 24, 2008
Messages
137
Re: Could water in the gas tank cause this problem?

Found the problem. The timing was off.
Turned the distributor a little and it runs great.
 

f_inscreenname

Commander
Joined
Aug 23, 2001
Messages
2,591
Re: Could water in the gas tank cause this problem?

Sounds like you are on the trail but........
I pulled the fuel water separator and dumped it into a glass. It was clean fuel until the last bit came out it was some rust colored water. The filter is only about 2 months old. I went ahead and replaced that but still no fix. We opened up the carb and you could see little water molecules sitting on the jets and such.
your not out of the woods yet. ;)
 
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