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No Anti-Siphon Valve

Posted: Tue Oct 18, 2022 7:09 pm
by dsthomas
Anyone else get a letter from cobalt saying their boat may not have an anti-siphon valve installed on the fuel tank?

I had to google what it does as I am not mechanically knowledgable. My limited understanding is that it can affect the way the boat runs if clogged and can be a safety issue if you have problems with your fuel lines. I'm going to call my dealer tomorrow to see what the repair process involves. I have a new 2022 R8 Surf. My boat has run great all year with no issues.

Anyway this weekend we were planning a cruise to see some of the fall colors. Should I put it up for the season and wait for the dealer to check it? We've put 70 hrs on it so far without issue. The letter said "MAY not have it installed" I'm either very lucky or my boat did have one installed.

Looking for input on how risky it is to keep running my boat before getting this checked???

Thanks!

Re: No Anti-Siphon Valve

Posted: Tue Oct 18, 2022 7:57 pm
by billk2632
The Anti Siphon valve is a required safety device. It is in the fitting that your fuel feed line connects to on top of the fuel tank. Inside that barb fitting in a small check valve. It's purpose is to prevent fuel from siphoning from the tank if the fuel feed line between the tank and fuel filter were to somehow rupture, get cut etc. The likelihood of happening is low - the line would have to rupture, be cut, or somehow come loose at the fuel filter side. In a worst case scenario the fuel could be siphoned out of the tank and into the bilge. It can also cause a problem when the check valve begins to stick, usually from age/corrosion etc. and can actually restrict fuel flow. The valve is a $20 item available at about any marine store, it's not something specific to Cobalt, SeaRay etc. Do you need to get it checked/replaced yes, is it critical to the point of don’t use the boat, no. I wonder how in the world Cobalt let something like this happen - I would not think theirs are any different than this one:

https://www.ebay.com/itm/354079534784?v ... c4f578357a

Re: No Anti-Siphon Valve

Posted: Wed Oct 19, 2022 1:29 pm
by dsthomas
billk2632 wrote: Tue Oct 18, 2022 7:57 pm The Anti Siphon valve is a required safety device. It is in the fitting that your fuel feed line connects to on top of the fuel tank. Inside that barb fitting in a small check valve. It's purpose is to prevent fuel from siphoning from the tank if the fuel feed line between the tank and fuel filter were to somehow rupture, get cut etc. The likelihood of happening is low - the line would have to rupture, be cut, or somehow come loose at the fuel filter side. In a worst case scenario the fuel could be siphoned out of the tank and into the bilge. It can also cause a problem when the check valve begins to stick, usually from age/corrosion etc. and can actually restrict fuel flow. The valve is a $20 item available at about any marine store, it's not something specific to Cobalt, SeaRay etc. Do you need to get it checked/replaced yes, is it critical to the point of don’t use the boat, no. I wonder how in the world Cobalt let something like this happen - I would not think theirs are any different than this one:

https://www.ebay.com/itm/354079534784?v ... c4f578357a
Thank you for the info!

Re: No Anti-Siphon Valve

Posted: Thu Oct 20, 2022 7:49 pm
by tfarmer
Cobalt sent a letter to my house that required signature.I guess they view it as pretty serious.

Re: No Anti-Siphon Valve

Posted: Thu Oct 20, 2022 8:54 pm
by billk2632
There is a USCG requirement for an anti siphon device, so yes as a builder Cobalt has to take it seriously.

Re: No Anti-Siphon Valve

Posted: Thu Oct 20, 2022 9:08 pm
by dsthomas
Yeah that's what concerned me was that the letter was certified mail and they were saying they take safety seriously. But from my research and the info I got from Bill sounds like they were in CYA mode. We went cruising today and no issues, going out again tomorrow. Dealer says they will get it installed when I take it in for service this winter.

Re: No Anti-Siphon Valve

Posted: Fri Oct 21, 2022 8:33 pm
by Krob1114
We didn't get a letter. Is it only certain models or certain years?

Re: No Anti-Siphon Valve

Posted: Sat Oct 22, 2022 7:51 am
by Big Block Power
Krob1114 wrote: Fri Oct 21, 2022 8:33 pm We didn't get a letter. Is it only certain models or certain years?
Its probably on the new even series boats.

Re: No Anti-Siphon Valve

Posted: Sat Oct 22, 2022 7:22 pm
by dsthomas
I'm thinking its the newer even R series as BB said... here is the letter if anyone is interested. It's pretty generic.

Re: No Anti-Siphon Valve

Posted: Sun Nov 27, 2022 9:10 pm
by xlint89
I've been dabbling in upping the HP on my engine and in the process was recommended to up the fuel pick up tube size to 1/2".

Once you go this big, I don't see an anti-siphon valve in 1/2"

How would the BIG HP guys get around this? 1k HP is not going to pull enough fuel through a 3/8" ID anti-siphon valve.

Re: No Anti-Siphon Valve

Posted: Mon Nov 28, 2022 8:58 am
by billk2632
Here is the USGC reg on anti-siphon requirements - there are a couple of configurations that are acceptable and don't specifically require an in-line mechanical anti-siphon valve. I know my SeaRay 290DA did not have the in-line valves, it had electric shutoff valves.

§183.568 Anti-siphon protection.
Each fuel line from the fuel tank to the fuel inlet connection on the carburetor must:

(a) Be above the level of the tank top; or

(b) Have an anti-siphon device or an electrically operated fuel stop valve:

(1) At the tank withdrawal fitting; or

(2) Installed so the line from the fuel tank is above the top of the tank; or

(c) Provided that the fuel tank top is below the level of the carburetor inlet, be metallic fuel lines meeting the construction requirements of §183.538 or “USCG Type A1” hose, with one or two manual shutoff valves installed as follows:

(1) Directly at the fuel tank connection arranged to be readily accessible for operation from outside of the compartment, and

(2) If the length of fuel line from the tank outlet to the engine inlet is greater than 12 feet, a manual shutoff valve shall be installed at the fuel inlet connection to the engine.

Re: No Anti-Siphon Valve

Posted: Tue Dec 06, 2022 9:42 am
by Krob1114
What if your boat does not have a carburetor?

Re: No Anti-Siphon Valve

Posted: Tue Dec 06, 2022 11:24 am
by billk2632
Carburetor/Throttle Body/Direct Injection, the anti-siphon prevention is the same.