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Water in fuel

Posted: Tue Jun 15, 2021 3:00 pm
by ocsjoe
Putting this out there to see if anyone else has had a similar experience. We received a "water in fuel" alert on one of our engines during our last outing. We limped back on one motor (long trip) and left the boat with service to see what is happening. A few interesting things were discovered

1) The 30SC (and maybe all SCs) do not come with fuel water separators from the factory. I didn't think to ask since this seems like a standard item for boats in this class.
2) Water appears to have entered through the vent that is right below the fuel fill. This is the working theory because water was found in the hose leading to the charcoal vapor canister as well as in the canister itself.
3) Water was found in one fuel filter. Service will be inspecting the other filter today.

The working hypothesis is somehow water entered the vent, came through the vapor canister and into the fuel cell. From there water traveled to the fuel filter where it set off the alarm and thankfully traveled no farther.

I am posting here to see if any others have experienced something like this, especially on the newer SC line. Also tapping into the group for other likely scenarios. It does not seem like water should be able to enter the vapor vent easily, especially enough to pass through the canister and into the fuel cell, if at all.

Thoughts?

-Joe
2021 30SC / Dual Mercury 300

Re: Water in fuel

Posted: Tue Jun 15, 2021 10:04 pm
by cmattj
Maybe? A long leaning right? Maybe?
I donโ€™t see it on the screen shots I took as the natural spray seems away.
I would suggest both engines would be setting a code or close.
Fuel sample maybe would suggest as I would get fuel from another source for awhile.
As maybe you got a batch with high water percentages.
Keep us posted๐Ÿ‘๐Ÿผ

Re: Water in fuel

Posted: Thu Jul 15, 2021 9:21 pm
by ocsjoe
Update:
The service team was not able to pass through the vent in any volume that would have led to water sitting in the vent hose leading to the charcoal canister. A small amount of water was found in the starboard fuel filter. A minimal amount of water, which was removed, was found in the tank after swapping out the filters and the charcoal canister. We did add fuel water separators for each engine.

Another item of note is that we were having fuel fill issues. We could not fill the tank quickly, and in some cases, even slowly. This is now resolved and we think it was related to the water in the vent hose not allowing air to pass freely.

In the end, it remains a mystery as to how there was so much water in the vent hose and the canister. On the positive side, I understand the fuel system way better than I ever wanted to, the boat now has fuel water separators that are easier to maintain than the fuel filters, and we are back out boating once again.

Re: Water in fuel

Posted: Thu Jul 15, 2021 10:25 pm
by AsLan7
ocsjoe wrote: Thu Jul 15, 2021 9:21 pm Update:
The service team was not able to pass through the vent in any volume that would have led to water sitting in the vent hose leading to the charcoal canister. A small amount of water was found in the starboard fuel filter. A minimal amount of water, which was removed, was found in the tank after swapping out the filters and the charcoal canister. We did add fuel water separators for each engine.

Another item of note is that we were having fuel fill issues. We could not fill the tank quickly, and in some cases, even slowly. This is now resolved and we think it was related to the water in the vent hose not allowing air to pass freely.

In the end, it remains a mystery as to how there was so much water in the vent hose and the canister. On the positive side, I understand the fuel system way better than I ever wanted to, the boat now has fuel water separators that are easier to maintain than the fuel filters, and we are back out boating once again.
.
Thanks for the follow-up OCSj!

Re: Water in fuel

Posted: Fri Jul 16, 2021 4:12 am
by Krob1114
I would remember the place I bought gas before that happened, and consider not buying gas there again.

Re: Water in fuel

Posted: Thu Nov 18, 2021 7:10 pm
by AlexV
Glad you got yours back up and running Joe. I'll be back down in the Cape the day after Thanksgiving. I haven't run my 25sc since February. I need to give it a good run. Every February I send it back to the Boat House for its yearly service I have to have items corrected. I'm a bit disappointed with Cobalt quality. Its not what it once was.