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Anti Siphon Valve

rush1

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Does anyone here run there boats without an anti siphon valve at the fuel tank pick up ? My boat vapor locked on the dam to dam run (97 Essex 454 carbureted ). I replaced my fuel pump and read some where to pull the valves that they are very restrictive and mine are ,you can barely blow through them . But now I'm wondering if they have some high flow valves ? I mean if you were to get a leak in the fuel pump or fuel line that things gonna drain the entire fuel tank
into the bilge ! :eek: Mine are 3/8 pipe thread right angle to 3/8 barbed . Should I replace them or not worry about it ? I know that they are Coast Guard mandated .
 

farmo83

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Alexi talked quite a bit about them in his fuel system. In summary yes they are very restrictive. In summary he said yes they are illegal to remove, it's also illegal to drive 56 in a 55.

Also the siphon valve actually stuck closed on our old family jet boat. Dad pulled it out and it's run fine in the 35 years it's been since then.
 

Deja_Vu

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I've had mine removed from both tanks and replaced with 90 degree elbows. No more issues.
 

rush1

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I've had mine removed from both tanks and replaced with 90 degree elbows. No more issues.
I think it was an old posting of yours I read , I'll leave them out and run it. I'm sure I'll be good to go from now on, Its unbelievable how restrictive those things are.
 

Deja_Vu

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I think it was an old posting of yours I read , I'll leave them out and run it. I'm sure I'll be good to go from now on, Its unbelievable how restrictive those things are.

Yeah mine were seized up pretty good, you couldn't get any decent pressure through them.
I'm not sure what the downside to taking them out would be... as long as our fuel lines are in good shape and the boat stays upright.
 

boatdoc55

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As I recall from many moons ago, one could remove them and replace with a manual shut-off valve and still be legal
 

ka0tyk

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As I recall from many moons ago, one could remove them and replace with a manual shut-off valve and still be legal

am i legal? like a 3' run from the tank to the first valve. then another valve after the filter and down to the pump...

18835667_10154878442574833_8907166577238117600_n.jpg
 

guest hs

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As I recall from many moons ago, one could remove them and replace with a manual shut-off valve and still be legal
I have a real hard time believing this. So if there is a fire in the engine compartment your going to open the hatch and turn off your manual fuel valve? I don't think so.
 

rush1

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I have a real hard time believing this. So if there is a fire in the engine compartment your going to open the hatch and turn off your manual fuel valve? I don't think so.
I thought about putting a shut off valve in mine which come out of the top of the tank (which is in the engine compartment) just in case I were to develop a leak in the fuel pump or hose at least I could shut it off , but you're right if its on fire your done.
 

guest hs

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Yah guess what happens when the hatch opens up you just feed the fire with all that delicious oxygen!
 

boatdoc55

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I have a real hard time believing this. So if there is a fire in the engine compartment your going to open the hatch and turn off your manual fuel valve? I don't think so.
Were you even around in the '70's?? We did a lot of stuff back then that you young'uns would shake yore head at these days.
 

rush1

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I was around back them too, before everyone was up your ass over nuthen !:p
 

Deja_Vu

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rush1

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I suppose we could add one of these units to help detect any issues with leaks/fumes.
We have room on the passenger dash next to the stereo. Was thinking of upgrading gauges anyway soon.

https://www.marine.com/products/10-xing1br/xintex-g-1b-gas-fume-detector-2-flush-mount-black

This one has auto Blower control

https://www.marine.com/products/11-...-detector-blower-control-wplastic-sensor-chro

How many total gallons of gas do our boats hold? I believe they hold 40 gallons a side is this correct?
 

Deja_Vu

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How many total gallons of gas do our boats hold? I believe they hold 40 gallons a side is this correct?

The newer ones are 80 Gals, I thought mine is 30 gals per side. Not really sure. Maybe I've never got it that low on fuel.

2005 Specs
Length 23 ft 3 in centerline length
Beam 7 ft 9 in
Deadrise at Transom 19 deg.
Dry Weight 4100 lb
Engine Stern Drive
Engine Mechanical - 7.4L
Engine Notes -
Fuel Gas/Petrol
Fuel Capacity 80 gal
Horsepower (total) 310
Hull Material Fiberglass
Hull Shape Modified Vee
Max Draft 1 ft 5 in
 

Taboma

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am i legal? like a 3' run from the tank to the first valve. then another valve after the filter and down to the pump...

18835667_10154878442574833_8907166577238117600_n.jpg

If you don't have an anti-siphon at the tank and unless all your fuel system lines and components up to the connection to the carb are above the top of the tank, this is not legal, regardless of the manual valves.
Here's the complete USCG regulations in PDF, rather than attach then entire document here's the link ---- Some very eye opening information contained here. Page 102 has a great picture of legal vs not.
http://www.uscgboating.org/assets/1/AssetManager/ABYC.1002.01.pdf
 

Rajobigguy

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If you are really struggling with enough flow, you can run a tee off the top of the tank with two anti siphon valve in parallel then tee them back together for a single line to the fuel pump.
 

Deja_Vu

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If you don't have an anti-siphon at the tank and unless all your fuel system lines and components up to the connection to the carb are above the top of the tank, this is not legal, regardless of the manual valves.
Here's the complete USCG regulations in PDF, rather than attach then entire document here's the link ---- Some very eye opening information contained here. Page 102 has a great picture of legal vs not.
http://www.uscgboating.org/assets/1/AssetManager/ABYC.1002.01.pdf

In this document regarding anti-siphon devices...Item #2 hits the nail on the head.

1. Some anti-siphon devices are spring loaded check valves. These valves have a specific cracking pressure and provide protection up to a specific head. Therefore, the anti-siphon valve must be selected or ordered to protect against the siphon head for a particular installation. © 2011 American Boat & Yacht Council, Inc. 94

2. Too high a cracking pressure may cause vapor lock. This has become an increasing problem with reformulated gasoline (RFG). Be sure to select the correct cracking pressure.

3. Some anti-siphon devices involve a bleed hole in the fuel pick-up tube, near the top of the fuel tank. The size of the hole is critical for a particular application. Each installation using this type of protection must be evaluated to assure its effectiveness. Too large a hole will bleed excessive air into the fuel flow effecting engine operation. Too small a hole may not stop fuel flow in the event of a fuel leak. This installation is used very infrequently because of inherent problems that may result.
 

boatdoc55

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In this document regarding anti-siphon devices...Item #2 hits the nail on the head.

1. Some anti-siphon devices are spring loaded check valves. These valves have a specific cracking pressure and provide protection up to a specific head. Therefore, the anti-siphon valve must be selected or ordered to protect against the siphon head for a particular installation. © 2011 American Boat & Yacht Council, Inc. 94

2. Too high a cracking pressure may cause vapor lock. This has become an increasing problem with reformulated gasoline (RFG). Be sure to select the correct cracking pressure.

3. Some anti-siphon devices involve a bleed hole in the fuel pick-up tube, near the top of the fuel tank. The size of the hole is critical for a particular application. Each installation using this type of protection must be evaluated to assure its effectiveness. Too large a hole will bleed excessive air into the fuel flow effecting engine operation. Too small a hole may not stop fuel flow in the event of a fuel leak. This installation is used very infrequently because of inherent problems that may result.
That's some good stuff, thanks. My post's are not an attempt to be a jackass, just to show how much was done in MY hayday 70's-80's that can't even be thought of NOW. This is when 18' jet boats were king and about 99% of what was running the lake and river back then.
 

Taboma

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That's some good stuff, thanks. My post's are not an attempt to be a jackass, just to show how much was done in MY hayday 70's-80's that can't even be thought of NOW. This is when 18' jet boats were king and about 99% of what was running the lake and river back then.

Well let's face it, it's a miracle any of us ole birds who lived through the 50's through the 70's can still possibly be living and breathing --- "Against all odds" baby, lol. :p
Even more amazing, the generations that proceeded us, those folks were clearly death defying in every way. :eek:

Looking back, the Jet Boat age was akin to the wild west, well it kinda was a West thing for sure. Rules --- ha ha -- we don't need no stinkin rules :rolleyes: The Orange County boat companies were grabbing deposits, closing up, changing names and relocating faster than the process servers could find them.
Up at Lake Arrowhead they started showing up and promptly cracking and sinking :mad: Used to party with Bob Burns of Cheetah fame. During those dark years if you rode in the back seat of one with your feet on the floor, hit a wave and your knee would hit you in the chin, feet STILL on the floor :eek: I'd give Bob shit about it and he'd just laugh and claim "Oh that's my patented Flexi-Bottom" --- ummm ok Bob. :rolleyes:
What does amaze me is how many survived, but mostly it seems the higher end ones, Bahner was a strong contender, he was a neighbor.

One of my concerns (In addition to family safety of course) as it applies to the these strict fuel system (and others) USCG regs is being denied an insurance claim because you removed, or changed, or defeated a component clearly required by those regs.
If you "Boom" and an investigator discovers a violation, there could be hell to pay.
 

rush1

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If you are really struggling with enough flow, you can run a tee off the top of the tank with two anti siphon valve in parallel then tee them back together for a single line to the fuel pump.
That is a great idea . I highly doubt a stock 310 hp 454 is running lean because of flow but the vapor lock problem is real and a lot of people are saying that valve is causing it , Think i'll tee it at the tank with 2 inline valves back into a single fuel line going to the transfer valve. That should eliminate the issue like you said. Thanks for that .:):):)
 

Rajobigguy

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Well let's face it, it's a miracle any of us ole birds who lived through the 50's through the 70's can still possibly be living and breathing --- "Against all odds" baby, lol. :p
Even more amazing, the generations that proceeded us, those folks were clearly death defying in every way. :eek:

Looking back, the Jet Boat age was akin to the wild west, well it kinda was a West thing for sure. Rules --- ha ha -- we don't need no stinkin rules :rolleyes: The Orange County boat companies were grabbing deposits, closing up, changing names and relocating faster than the process servers could find them.
Up at Lake Arrowhead they started showing up and promptly cracking and sinking :mad: Used to party with Bob Burns of Cheetah fame. During those dark years if you rode in the back seat of one with your feet on the floor, hit a wave and your knee would hit you in the chin, feet STILL on the floor :eek: I'd give Bob shit about it and he'd just laugh and claim "Oh that's my patented Flexi-Bottom" --- ummm ok Bob. :rolleyes:
What does amaze me is how many survived, but mostly it seems the higher end ones, Bahner was a strong contender, he was a neighbor.

One of my concerns (In addition to family safety of course) as it applies to the these strict fuel system (and others) USCG regs is being denied an insurance claim because you removed, or changed, or defeated a component clearly required by those regs.
If you "Boom" and an investigator discovers a violation, there could be hell to pay.

Remember that back in those days when jet boats and
v-Drive flat bottoms were the the most prevailent boats
on the lakes, most of them had no engine covers so your chance
of having a leak and not knowing it before something really bad happened
were much better.
 

rush1

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The newer ones are 80 Gals, I thought mine is 30 gals per side. Not really sure. Maybe I've never got it that low on fuel.

2005 Specs
Length 23 ft 3 in centerline length
Beam 7 ft 9 in
Deadrise at Transom 19 deg.
Dry Weight 4100 lb
Engine Stern Drive
Engine Mechanical - 7.4L
Engine Notes -
Fuel Gas/Petrol
Fuel Capacity 80 gal
Horsepower (total) 310
Hull Material Fiberglass
Hull Shape Modified Vee
Max Draft 1 ft 5 in

Thanks for the 411 . I know I have put 36 gallons in one of my tanks so I figured they were 40 gallon tanks each.
 

Ziggy

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I've had mine removed from both tanks and replaced with 90 degree elbows. No more issues.
Omg, that's so illegal:D:D. Sure hope the safety check point cops aint checking for check valves:p:cool::D
Check, check, testing 123:D.
.
You coming home this weekend?
 

Taboma

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Remember that back in those days when jet boats and
v-Drive flat bottoms were the the most prevailent boats
on the lakes, most of them had no engine covers so your chance
of having a leak and not knowing it before something really bad happened
were much better.

For sure, they were well vented as well, lol
Besides my Hondo V-drive flat always had an inch or so of water sloshing up between my legs when I decelerated, kept my nuts cooled off :D Eventually nuts sufficiently cooled, I'd have my buddy drive while plowing and I'd climb to the stern, reach around the dry pipes, burn the fuck out of the tender insides of my arm and pull the plug for a minute or so :mad: Most of us wore header burns like a medal of honor !! :p

The USCG Regs I linked are filled with numerous and rigorous fuel system testing requirements. Those are seriously eye-opening and I doubt that even the majority of current custom boat manufacturers have performed them or even comply.
 

Deja_Vu

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Omg, that's so illegal:D:D. Sure hope the safety check point cops aint checking for check valves:p:cool::D
Check, check, testing 123:D.
.
You coming home this weekend?

LOL, :) The fittings I have look identical to the anti-siphon valves, so it would be difficult to check for compliance with a visual inspection.

Yep, hoping to launch really early Friday!
 

boatdoc55

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Remember that back in those days when jet boats and
v-Drive flat bottoms were the the most prevailent boats
on the lakes, most of them had no engine covers so your chance
of having a leak and not knowing it before something really bad happened
were much better.
Tru-dat
 

boatdoc55

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For sure, they were well vented as well, lol
Besides my Hondo V-drive flat always had an inch or so of water sloshing up between my legs when I decelerated, kept my nuts cooled off :D Eventually nuts sufficiently cooled, I'd have my buddy drive while plowing and I'd climb to the stern, reach around the dry pipes, burn the fuck out of the tender insides of my arm and pull the plug for a minute or so :mad: Most of us wore header burns like a medal of honor !! :p

The USCG Regs I linked are filled with numerous and rigorous fuel system testing requirements. Those are seriously eye-opening and I doubt that even the majority of current custom boat manufacturers have performed them or even comply.
I worked on so many buddies boats at the river in those days I should have bought stock in A&D ointment back then. That was my go to after working on those DAMN jet boats. Yes, still wear a couple scars from them damn things but the A&D did a great job.
 

Taboma

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I worked on so many buddies boats at the river in those days I should have bought stock in A&D ointment back then. That was my go to after working on those DAMN jet boats. Yes, still wear a couple scars from them damn things but the A&D did a great job.
A&D and BEER lotsa BEER, lol :D
 

ka0tyk

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If you don't have an anti-siphon at the tank and unless all your fuel system lines and components up to the connection to the carb are above the top of the tank, this is not legal, regardless of the manual valves.
Here's the complete USCG regulations in PDF, rather than attach then entire document here's the link ---- Some very eye opening information contained here. Page 102 has a great picture of legal vs not.
http://www.uscgboating.org/assets/1/AssetManager/ABYC.1002.01.pdf

its a belly tank, everything sits above it. all lines, filters, carb, pump, etc.
 

Taboma

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its a belly tank, everything sits above it. all lines, filters, carb, pump, etc.
Then if I'm reading it and viewing the example drawings correctly, you should be good to go without an anti-siphon valve.
 

guest hs

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its a belly tank, everything sits above it. all lines, filters, carb, pump, etc.
What happens if the fuel line were to come off, whether it burned off where it attaches to the engine or broke of there and fell into the bilge below the tank?
 

ka0tyk

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What happens if the fuel line were to come off, whether it burned off where it attaches to the engine or broke of there and fell into the bilge below the tank?

have you ever bent a steel braided hose? if that hose came off the fuel pump it would spring straight outwards. maybe a dribble of fuel. about a foot and a half higher than the tank.
 

Taboma

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What happens if the fuel line were to come off, whether it burned off where it attaches to the engine or broke of there and fell into the bilge below the tank?

Hard to account for every "What if", but the USCG regs in his case do not require the anti-siphon valve.
There are regs that require fuel line support as well as supporting filters, even a maximum distance (12" from engine) for a non-engine mounted fuel pump.

The several boat fires I've witnessed out on the lake at Havasu, they monitor and act like they're fighting it, but in reality so long as the vessel isn't endangering other craft, shore etc --- they let it burn to the waterline. They want the gas to burn off to keep it out of the lake.

Anti-Siphon-1.JPG
Anti-siphon-2.JPG
 

Go-Fly

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How much vacuum does it take to open an anti-siphon valve on a boat?
 

guest hs

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Hard to account for every "What if", but the USCG regs in his case do not require the anti-siphon valve.
There are regs that require fuel line support as well as supporting filters, even a maximum distance (12" from engine) for a non-engine mounted fuel pump.

The several boat fires I've witnessed out on the lake at Havasu, they monitor and act like they're fighting it, but in reality so long as the vessel isn't endangering other craft, shore etc --- they let it burn to the waterline. They want the gas to burn off to keep it out of the lake.

View attachment 676156 View attachment 676157
What if, exactly remember its a boat and anything can happen. Most boats don't have a steel braided line from the tank to what ever engine connection point it has. Most are just rubber fuel lines and if that line comes off for what ever reason and it falls in the bilge lower then the tank IT WILL DRAIN FUEL IN THE BILGE!
 

Taboma

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What if, exactly remember its a boat and anything can happen. Most boats don't have a steel braided line from the tank to what ever engine connection point it has. Most are just rubber fuel lines and if that line comes off for what ever reason and it falls in the bilge lower then the tank IT WILL DRAIN FUEL IN THE BILGE!

Is it possible, yes, probable ? Assuming a long enough piece isn't supported and depending on how high above the tank it's been routed and how far below the fuel level in the tank it falls and if it has enough siphon to over come the head pressure to pull the fuel up and out of the tank --- well yes it could. OR what if the hose falls off or fails on the pressure side of the remote mounted electric fuel pump, and pumps gas into the bilge ? Does everybody have their electric fuel pump wired across an oil pressure switch ?

I'm not arguing that you're not making a valid point, I'm stating what's USCG legal or not. At least under your scenario your insurance company can't deny the claim.

Does every custom boat have their metallic fuel fillers properly grounded ? Have all our fuel tanks been stress tested per USCG regs ? Those Regs are seriously complex when you really dig into them.
 
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