Anti-Siphon Valve

Milkman01

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Joined
Apr 22, 2012
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5
I have a 1993 Tracker Magna DC and a 2003 Johnson 90hp 4strk with a 27-gal under floor tank. My question is that I can't get the bulb to pickup fuel out of the tank. I've replaced the vent, fuel, and line with bulb and new connections to tank. I removed the pickup tube inside the tank and the screen was free and clear of any obstructions. Is there supposed to be a spring and ball in either fitting above the pickup tube because I can see through both of the fittings and the pickup tube. Thanks for any input on this.
 

Beefer

Lieutenant Commander
Joined
Aug 4, 2008
Messages
1,737
Re: Anti-Siphon Valve

An anti-siphon can and does fail frequently, so I would leave it out. It is not required for it to work.

Since just about everything tank-side is new, you may want to look for something obstructing the flow on the engine side. Make sure the engine's fuel lines are in good condition. I think the motor is new enough where ethanol shouldn't be a problem, but you shouldn't rule out deteriorated fuel line interior due to ethanol exposure. Unlikely, but make sure the all filter(s) on the motor are clean.

You may have the bulb installed wrong, make sure the arrow(s) point towards the motor, and not back to the fuel tank.

Are you sure the vent is open fully?

That's about all I can think of now.....
 

Thalasso

Commander
Joined
Jan 18, 2011
Messages
2,876
Re: Anti-Siphon Valve

An anti-siphon can and does fail frequently, so I would leave it out. It is not required for it to work.

Op states tank is under floor

Here's the reg:

FEDERAL LAW
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 Sec. 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 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.
 

Milkman01

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Joined
Apr 22, 2012
Messages
5
Re: Anti-Siphon Valve

Arrow is pointed towards the engine and I tried a new hose which was a 45.00 waste. Vent is clear. I checked it when I replaced the vent hose. Thanks for the troubleshooting.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,417
Re: Anti-Siphon Valve

Op states tank is under floor

Here's the reg:

FEDERAL LAW
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 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

It's an either or situation. As long as the fuel inlet connection on the carb is above the level of the tank top, your good to go.
 

Milkman01

Recruit
Joined
Apr 22, 2012
Messages
5
Re: Anti-Siphon Valve

The motor is fuel- injected. And the barb fitting above the tank and block fitting are both aluminum. Could the pickup tube be too loose and need replacing?
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,019
Re: Anti-Siphon Valve

I have a 1993 Tracker Magna DC and a 2003 Johnson 90hp 4strk with a 27-gal under floor tank. My question is that I can't get the bulb to pickup fuel out of the tank. I've replaced the vent, fuel, and line with bulb and new connections to tank. I removed the pickup tube inside the tank and the screen was free and clear of any obstructions. Is there supposed to be a spring and ball in either fitting above the pickup tube because I can see through both of the fittings and the pickup tube. Thanks for any input on this.

Welcome to iboats.

Is this a new to you boat/motor? Is it a new problem?

Depending on a variety of factors i.e. your built in tank is 19 years old so...... who knows if it had a ball and spring in the pick up.

The majority of failure to pick up fuel is normally a leak in the line. There might be a small leak in the pickup tube too. The tiniest leak will prevent fuel flowing.

Once we get a bit further into this I will move the post to the proper place. ;)
 

Milkman01

Recruit
Joined
Apr 22, 2012
Messages
5
Re: Anti-Siphon Valve

Bob the boat is new to me. I have put about 10hrs run time on it before this happened and ran it at all speeds with no problems.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,019
Re: Anti-Siphon Valve

Here is my guess ;) You really need to inspect (remove if you can) the fuel pick up and maybe pressure test it........ look for pin holes.

I am positive you have encountered a small crack in a plastic straw and it is near impossible to drink past that crack. Perhaps the leak is a tiny bit lower on the fuel line ;)
 

Beefer

Lieutenant Commander
Joined
Aug 4, 2008
Messages
1,737
Re: Anti-Siphon Valve

An anti-siphon can and does fail frequently, so I would leave it out. It is not required for it to work.

Op states tank is under floor

Here's the reg:

FEDERAL LAW
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 Sec. 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 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.

It would be really unusual for an outboard with a fuel cell/tank below deck to be required to have an anti-siphon. In fact, if I had to guess, I'd say 75% of recreational boats don't require an anti-siphon. Straight inboards are the only ones I could see needing one with typical installations.
 

Milkman01

Recruit
Joined
Apr 22, 2012
Messages
5
Re: Anti-Siphon Valve

Took my portable tank from my other boat opened the fill cap and inserted the pickup tube and my primer bulb hose to the motor. Pickup tube was two feet below the motor and worked great. Reinstalled pickup tube assembly and it failed again. So I shortened primer bulb fuel line and it works now. I left it primed for and hour and went and checked the bulb it was still hard. Will give it a test later on in the week. Thanks for all your suggestions.
 
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