"Marine" parts vs. cheaper ones

[BOFH]

There has been a lot of talk lately about "marine" carbs, distributers and ignitions. Everyone is questioning the laws and enforcement in a given spot... Since this is a major topic, I want to start a thread on it.
Law - Everywhere. It is a US Coast Guard thing, and all vessals must comply. Enforcement varries, but it is the law everywhere.
Difference - "Spark Protected" - Starters, Alternators, Points, and motors spark. It is how they work. "Spark Protected" or "Ignition Protected" means that any vents are sealed, vented outside the boat, or grounded. The last part can just be a screen, and is why K&N filters are spark arrestors.
Difference - Carbs - This is simple. All vents are to the inside of the carb. An FI system would have to have sealed electronics, and internal venting to ge legal, and safe.
Safety - Why am I doing this? Several years ago, I saw a boat blow up at a fuel dock. It was an outboard sport fisher. It turned out that the guy replaced his blower with a plane old squirel cage from the hardware store. He filled his tank, and some gas spilled, and ran down the deck. Like a good capitan, he hit his bilge fan before starting the external moter. This is all good safety, right up to the point where the non spark protected fan ignited the fuems below deck. It split the boat right allong the hull seam. The owner survived, but was blown about 30 feet up, and 20 feet forward. If anyone had been below, they would probably not have survived.
Everyone talks about how the engine compartment is open, but gas fumes sink. This is why the blower is in the bottom. Think about this when you are looking to save $100. Hell, thats not even a fill up these days. :-)

[Boatcop]

Good Topic.
To understand the need for marine shielded components you have to understand what is occuring in the engine compartment.
Gas fumes sink and collect in the bottom of the boat. Any spark and you have an explosion. It's a well known fact that the fumes from 1 cup of spilled gasoline equal the explosive force of 10 sticks of TNT.
Marine shielded alternators, generators, distributers, and starters have wire mesh around any openings. This allows proper ventilation/cooling of the component, while containing the spark inside the unit. When the fuel/air ratio reaches an explosive state, an explosion still occurs, but is contained harmlessly within the component. Without shielding the small explosion leaves the component and ignites the fumes in the rest of the engine compartment making the whole boat go BOOM!
Fuel pumps are a little different. Automotive fuel pumps have a weep hole, which lets the owner know when there is a diaphram failure. In a car, this is little more than an annoyance resulting in wasted gas and a stain on the driveway.
But in a boat, the fuel collects in the bilges and turns the boat into a potential bomb. FOr this reason, marine fuel pumps have a nipple where the hole would be, and a hose from the nipple to the carb intake. With this set-up, any leaked fuel is sucked back through the carb.
Backfire flame arrestors are the thngs that must be installed on the intake of all inboard gas powered boats. These are to prevent any backfire flames from igniting any gas fumes, material or people on the boat.
Carburators are not included in the list of required marine components, but hoses, wiring and fittings are.
Bilge blowers are kind of mis-labled. They don't "blow" fresh air into the bilge, but rather suck the fumes out. They should be marine type, installed in the bilge exhaust ducting, with the end of the duct (hose) in the lowest part of the bilge, but not so low to be submerged in any fluids that may be there.
I've investigated dozens of boat fires, and in nearly every case, one or more of the components were not marine shielded. If a marine mechanic installed or re-installed any of those components, then they would be liable for the explosion and resulting fire. If the owner installed the non-marine devices, their insurance would most likely deny coverage.
They may be a few dollars more. But what's a few hundred bucks on a $30,000+ boat.

[Liberator TJ1984]

Alan, I am taking that you do not have to run a marine style carb in an enclosed compartment..I thought you did ??

[RandyH]

Liberator TJ1984:
Alan, I am taking that you do not have to run a marine style carb in an enclosed compartment..I thought you did ??Good Question, I thought the J tubes and the seals where required in the Marine Carb. I hope you can clarify here Alan, Thanks in Advance.
Randy

[Boatcop]

I haven't seen "Marine Type" or "Coast Guard Approved" carburators, however there are standards which must be followed on carburators used in Marine Applications. Those standards from the Code of Federal Regulations are: (33 CFR)
Sec. 183.526 Carburetors.
(a) [Reserved]
(b) Each carburetor must not leak more than five cubic centimeters
of fuel in 30 seconds when:
(1) The float valve is open;
(2) The carburetor is at half throttle; and
(3) The engine is cranked without starting; or
(4) The fuel pump is delivering the maximum pressure specified by its manufacturer.
(c) Each updraft and horizontal draft carburetor must have a device that:
(1) Collects and holds fuel that flows out of the carburetor venturi section toward the air intake;
(2) Prevents collected fuel from being carried out of the carburetor assembly by the shock wave of a backfire or by reverse air flow; and
(3) Returns collected fuel to the engine induction system after the engine starts,
The question would be whether a standard automotive type carb would conform to these standards. When I ran the Spectras on the River for the Coast Guard in the late '70's, we had 800 CFM dbl pumper Holley's on our 454s. These were installed by Burbank Marine to COast Guard specifications and certified as meeting required standards.
What they are looking for is the inability for the carburator to introduce liquid fuel into the engine compartment through the throttle body.
If anyone's interested, the entire list of required motorboat equipment and their construction requirements is at:
CFR Title 33 (http://www.access.gpo.gov/nara/cfr/waisidx_01/33cfr183_01.html)

[Hotcrusader76]

The only true "safety features" on a Marine carb that I have researched are three things:
1.J-tubes for fuel venting
2.Throttle shafts that won't leak outside the carb body
3. Anti-roll over squirters
Other than that, the fuel metering is a little richer on the bottom end, off-road style spring loaded needle and seats, and the certain Marine carbs are corrosion protected.
All of these features can be a no cost up-grade when overhauling an automotive Holley carburetor.
-Ty
[ August 14, 2002, 06:45 PM: Message edited by: Hotcrusader76 ]

[RandyH]

Thanks guys, this is great info.
randy

[Boatcop]

One last note on the enforcement of these standards.
The Coast Guard requires them on all new vessels sold in the US, and manufactured after the date each specific standard was adopted. The requirement is for manufacturers and dealers. Most (and I emphasize MOST) state laws don't address the standards in their state statutes, and even fewer require the owner to maintain those standards.
What this means is that in many areas, the owner can do anything they want to their boat's engine, (with the exception of back-fire flame protection). If Joe Back-Yard-Mechanic wants to replace that $300 Marine starter with a $19.95 Pep-Boys rebuild, no law prevents him from doing it, or running it. eek!
However, that fact will come out when the explosion and fire is investigated, and the insurance claim will be denied. (Notice I said "WHEN"?)
Keep that in mind when your motor-head brother-in-law says he can fix your boat a lot cheaper than the Merc dealer downtown can.

[79Hawaiian]

Great topic. I have been a bit (or a lot) ignorant on the topic. My boat does not even have a blower but I did have an experience when the front bowl was spraying gas on the manifold due to a failed gasket. I posted a previous topic asking about replacement distributor suggestions and was leaning towards an automotive product. Looking back to the time my manifold was saturated with gas I am thankful I had the shielded distributor! Screw the boat, I don't want to burn on of my good friends who are sitting in back. Boats can be replaced, god forbid I caused a friend or family member to be injured. That’s when the $100 really becomes insignificant.

[Rexone]

I wish we could get more people to realize the importance of these marine parts. We are constantly trying to educate people why to buy and use the more expensive marine fuel pumps, distributors, starters, alternators...the list goes on. It's amazing to me the number of people who just don't get it. I guess they've never seen or heard of gasoline exploding.
On the insurance aspect, I'm sure claims would be denied when it's discovered non approved marine parts have been used. I'm also guessing that anyone that knowingly installs a non-marine approved part, weather it be a mechanic or an individual doing his own work, that ends up causing an explosion and death or injury could likely be held liable in a lawsuit situation. It's just all food for thought when replacing these items on our boats. It just doesn't pay to take a chance for a hundred or even a few hundred bucks. And don't be lulled into thinking open engines are exempt from problems. Like the others have pointed out, fuel vapor sinks and collects. Consider no wind, a fuel leak, and hitting that automotive starter you just got from Pep Boys for $50...if there's enough vapor collected it's adios boat, along with anyone and anything close by.

[79Hawaiian]

Question: I have a marine fuel pump on my Ford 460. The hose runs up the block, across the manifold between the carb and valve cover, and back down the back side of the block into the bilge by the pump. Boatcop metioned it should connect to the carb. There is nowhere for it to connect. Am I missing something?

[Rexone]

That's definately not where it should be going. Normally there's a small tube on most flame arresters that the small tube slides onto, thus routing any fuel leakage directly back into the carburetor. Now if you're not running a flame arrester (problem in itself), you need to rig that hose up some way to dump into the carb. The bilge is the worst place it could be going.

[Hotcrusader76]

79Hawaiian:
Question: I have a marine fuel pump on my Ford 460. The hose runs up the block, across the manifold between the carb and valve cover, and back down the back side of the block into the bilge by the pump. Boatcop metioned it should connect to the carb. There is nowhere for it to connect. Am I missing something?You will have to "T" that line into a hose that comes off the baseplate, otherwise add one to the existing baseplate if it has been tapped/plugged.
-Ty

[stressedout]

Hotcrusader76:
The only true "safety features" on a Marine carb that I have researched are three things:
1.J-tubes for fuel venting
2.Throttle shafts that won't leak outside the carb body
3. Anti-roll over squirters
Other than that, the fuel metering is a little richer on the bottom end, off-road style spring loaded needle and seats, and the certain Marine carbs are corrosion protected.
All of these features can be a no cost up-grade when overhauling an automotive Holley carburetor.
-TyAnd the fuel level is below any gasket therefore cannot leak externally. An automotive carb does not have this feature therefore cannot be altered to marine specs.

[kevnmcd]

79Hawaiian:
Question: I have a marine fuel pump on my Ford 460. The hose runs up the block, across the manifold between the carb and valve cover, and back down the back side of the block into the bilge by the pump. Boatcop metioned it should connect to the carb. There is nowhere for it to connect. Am I missing something?79-I have the same problem with my carb...no place to put that failure line from the fuel pump. I went to the local auto parts store and got a brass fitting, drilled a hole in the top of my flame arrestor and now have my failure line attached to that. It cost me all of about $2 and about 20 min. of my time. Hope that helps ya.

[BOFH]

Wow! This took off... To bad you don't get modded up for starting a good topic. :-) A few things...
I haven't seen "Marine Type" or "Coast Guard Approved" carburators, however there are standards which must be followed on carburators used in Marine Applications. Those standards from the Code of Federal Regulations are: (33 CFR) The Costies say that any Carb labeled "Marine" must conform to current standards. While there is no enforcement, there is liability to the company... Major "Marine" carbs will pass.
What this means is that in many areas, the owner can do anything they want to their boat's engine, (with the exception of back-fire flame protection). If Joe Back-Yard-Mechanic wants to replace that $300 Marine starter with a $19.95 Pep-Boys rebuild, no law prevents him from doing it, or running it. The first is "gross negligence." If the Costies feel like it, they can gound you for operating an unsafe vessel. If they feel real mean, they will note your insurance, and later call them and tell them about your unsafe part. This usually results in canceld coverage until it is fixed. (Seen it happen, but the costies have to really hate you)
And the fuel level is below any gasket therefore cannot leak externally. An automotive carb does not have this feature therefore cannot be altered to marine specs Depends on the carb. The only difference between Carter Marine and Auto is the lid. I have put a Marine lid on an Auto body many times...
In addition... Liability includes the people on the boat, the people near the boat, other boats and docs wich catch fire, polution, removal of the damaged boat(s)... It can be well over the value of your boat, and insurance may deny the whole thing.
Also, I can't say enough good things about gas fume detectors and CO detectors.

[gstark]

I think it is about time that these facts are made clear.
I have read (to my concern) too many replies that minimize the differences between marine and non-marine carbs.
Its about time people understand that there is more to this topic than J-tubes and slabbed throttle shafts.
This is about consequences. Consequences of the accidents that have happened (injury, loss of life and property) and the actions taken to prevent them in the future.
This is one reason why we have regulatory bodies with oversight in industry, such as FAR/JAR regs, ASME B&PV codes, etc. I don't think any of use would want to be in a boiler explosion because someone took the "cheap" way out of a pressure vessel design. Or why there are stringent requirements for fire protection in commercial, regional, or biz aircraft.
So why take shortcuts on a boat? To save money?
Its only your life, maybe your best buddy, your wife or your childs. Ask yourself if these are worth the couple of dollars saved for the risk that results.
By the way, USCG certified Holleys have the same front/rear split bowl as non-marine carbs, so it is incorrect that the fuel level is below gasket sealing surfaces.
[ August 15, 2002, 12:46 PM: Message edited by: gstark ]

[superdave013]

What about us guys with exposed engines? I have not engine compartment or cover. I thought I didn't have to use the marine goodies (other than arresters in scoops) but I could be wrong.
Boat Cop, is my thinking correct??

[Hotcrusader76]

gstark:
I think it is about time that these facts are made clear.
I have read (to my concern) too many replies that minimize the differences between marine and non-marine carbs.
Its about time people understand that there is more to this topic than J-tubes and slabbed throttle shafts.
This is about consequences. Consequences of the accidents that have happened (injury, loss of life and property) and the actions taken to prevent them in the future.
This is one reason why we have regulatory bodies with oversight in industry, such as FAR/JAR regs, ASME B&PV codes, etc. I don't think any of use would want to be in a boiler explosion because someone took the "cheap" way out of a pressure vessel design. Or why there are stringent requirements for fire protection in commercial, regional, or biz aircraft.
So why take shortcuts on a boat? To save money?
Its only your life, maybe your best buddy, your wife or your childs. Ask yourself if these are worth the couple of dollars saved for the risk that results.
By the way, USCG certified Holleys have the same front/rear split bowl as non-marine carbs, so it is incorrect that the fuel level is below gasket sealing surfaces.I concurr with the fuel level gasket theory....Yes your right about the loss of life issue and safety factor, but those of us running open bay engine set-ups and we run the boat for about 15 minutes at a time tops....there is no reason to spend the extra dollar on the Marine carb. Now and off-shore boat running over heavy chop with an "enclosed" set-up..By all means do your insurance company a favor and buy Marine versions.
-Ty

[Boatcop]

There's no distinction for enclosed or open engine compartments. The regs state "Marine Use" only.
There are references for "Open" construction and "Closed" construction. Any boat with an inboard engine is "closed" construction.
An "open" construction boat is one with no engine or an outboard engine, no fixed tanks, and no spaces capable of entrapping fuel vapors.
The "open" and "closed" designations are for applying fire extinguisher and ventilation requirements only.
The regs also apply the standards to boats constructed after a certain date, usually the date the specific regulation went into effect.
An early 60's inboard may be "legally" exempt from those requirements, since they weren't in effect at the time of construction, but from a safety standpoint, all those boats should be retrofitted with properly shielded marine type components.

[gstark]

Hotcrusader76:
I'm not quite sure you understand where I am coming from.
I do understand your position, I grew up rodding around SoCal, building engines and doing engine swaps. So I am really familiar with the economies of cars and boats.
But - when safety is an issue, there are no shortcuts.
You have done a fine job convincing yourself (and perhaps others) that usage of non-marine carbs is acceptable because you have an open engine and only run it for a short duration. Unfortunately, your rationale is incorrect because it describes "how" you use your boat, but it does not address the potential effects and consequences of a fuel/carb ignition scenario.
Even if your engine is fully open, with no dogbox, it is easy to have a carb fire. How many times have you seen floats stuck with fuel spilling over? I've seen this many times. Even burned up a truck this way. Add to this a bilge full of fumes (remember, fuel vapor density is greater than air) that could collect in between your 15 minute runs, even in a ventilated area.
Now add an ignition source (standard distributor) and guess what happens.
That is what marine rated equipment is all about. Its design is to minimize risk and prevent life and property damage. The cost of this marine rating is due to the limited market, certainly not to the equipment itself.
I work in the aircraft design industry, and get involved in system certification. I can only tell you that short cuts and bypassing safety items is simply unacceptable in this area. Just look at the consequences of an accident - no further explanation required.
I've seen too many accidents, been in a few myself, to know that in an instant, your life can change. Perhaps the perspective I have is something that comes with time and experience.
I'm just trying to share this, so that you, or anyone else doesn't learn the hard way.

[Hotcrusader76]

gstark:
Hotcrusader76:
I'm not quite sure you understand where I am coming from.
I do understand your position, I grew up rodding around SoCal, building engines and doing engine swaps. So I am really familiar with the economies of cars and boats.
But - when safety is an issue, there are no shortcuts.
You have done a fine job convincing yourself (and perhaps others) that usage of non-marine carbs is acceptable because you have an open engine and only run it for a short duration. Unfortunately, your rationale is incorrect because it describes "how" you use your boat, but it does not address the potential effects and consequences of a fuel/carb ignition scenario.
Even if your engine is fully open, with no dogbox, it is easy to have a carb fire. How many times have you seen floats stuck with fuel spilling over? I've seen this many times. Even burned up a truck this way. Add to this a bilge full of fumes (remember, fuel vapor density is greater than air) that could collect in between your 15 minute runs, even in a ventilated area.
Now add an ignition source (standard distributor) and guess what happens.
That is what marine rated equipment is all about. Its design is to minimize risk and prevent life and property damage. The cost of this marine rating is due to the limited market, certainly not to the equipment itself.
I work in the aircraft design industry, and get involved in system certification. I can only tell you that short cuts and bypassing safety items is simply unacceptable in this area. Just look at the consequences of an accident - no further explanation required.
I've seen too many accidents, been in a few myself, to know that in an instant, your life can change. Perhaps the perspective I have is something that comes with time and experience.
I'm just trying to share this, so that you, or anyone else doesn't learn the hard way.And again I agree with you...My training first stemmed from the ranks of the Military and working on Avionics systems mainly Radar and VHF/UHF systems and safety has always been number one.
At no time do I mislead a customer into believing that the automotive carburetor is the best option with price over safety. Funny thing is I can minimize the risk of fuel spill alone with J-tubes, but with a carburetor having an overflow issue, J-tubes alone will not help! Yes floats do malfuction and stick on occasion, dependant on how they were rigged inside. Just so people understand, at no time would I sell my product with the belief that it's the same as a marine version, and the differences only lye within the J-tubes and shafts. But any carburetor guru will tell you, float problems are the number one blammed part on a carburetor, and keeping them functioning without over-flowing is tricky. But an overflowing carburetor at 3000RPM, J-tubes or not, grooved shafts (not slabbed)or not, will never stop the carburetor from spilling all over the engine when you begin to idle down, specially when these guys run these "Craftsmen" Size fuel pumps running 50psi...when they should be at 7-8psi. It is only going to slow the affects of the spill on the motor.
But hell.....Holley has engineered the design for a Marine safe fuel system, and the coasties (Dept. of Transportation) bought off on it. Whether it was up to par or not....but who is to compete?
[ August 15, 2002, 06:54 PM: Message edited by: Hotcrusader76 ]

[Hotcrusader76]

Now when it comes to electrical components....I think the Marine versions are not a bad option. Fuel fumes and spark aren't good combos outside the motor, and a well engineered electronic component is a must in that sort of enviroment. Also the manner in which the epoxy is layed on the circuit boards helps prevent shock damage (ESD) as well as vibration damage due to severe duty use.

[Lake Lifeguard]

Hi Folks,
I just thought I would throw my 2 cents into this. Although the Code of Federal Regulations does not mandate "Marine" components for anyone other than "dealers" and "manufacturers" and permits modifications by the end user, boaters should be very careful about compliance with their state regs which might mandate compliance.
Then there is the issue of modifications invalidating your insurance should an accident occur. Insurance companies are in the business of making money not paying claims so if you give them a way out they will take it.
Lastly, should you sell the boat at some point you would in fact be acting as a dealer and would be responsible for restoring the vessel to CFR 33 standards and various state standards as well. For example, if you sell a vessel in Calif. you would be responsible to make sure that the vessel is "effectively" muffled. Failure to do so could result in costly litigation if something were to happen.
Lets look at a hypothetical situation. You sell your boat as is to someone who wants it "as is". It burns at the fuel dock and the insurance companies involved start looking for 3rd parties to absorb liability. They hire a marine surveyor who inspects the boat and finds that the fuel system was not in compliance with the standards. Then they turn to you saying that you sold a modified marine engine that violated the law and therefore are responsible for the fire and any consequence of the fire such as the dock, other boats and structures.

[Hotcrusader76]

Lake Lifeguard:
Hi Folks,
I just thought I would throw my 2 cents into this. Although the Code of Federal Regulations does not mandate "Marine" components for anyone other than "dealers" and "manufacturers" and permits modifications by the end user, boaters should be very careful about compliance with their state regs which might mandate compliance.
Then there is the issue of modifications invalidating your insurance should an accident occur. Insurance companies are in the business of making money not paying claims so if you give them a way out they will take it.
Lastly, should you sell the boat at some point you would in fact be acting as a dealer and would be responsible for restoring the vessel to CFR 33 standards and various state standards as well. For example, if you sell a vessel in Calif. you would be responsible to make sure that the vessel is "effectively" muffled. Failure to do so could result in costly litigation if something were to happen.
Lets look at a hypothetical situation. You sell your boat as is to someone who wants it "as is". It burns at the fuel dock and the insurance companies involved start looking for 3rd parties to absorb liability. They hire a marine surveyor who inspects the boat and finds that the fuel system was not in compliance with the standards. Then they turn to you saying that you sold a modified marine engine that violated the law and therefore are responsible for the fire and any consequence of the fire such as the dock, other boats and structures.Then hire a hitman...because it just wasn't meant to be....LOL.....
That would suck....Great point!

[propless]

Lake –
You hit the nail on the head. Very few people have ethics today, nobody takes responsibility for their actions – lets blame our parents or our teachers or grandparents.
The fact is, there are specific recommendations that should be followed and owner / buyer beware that if you elect to save a dime to avoid paying a buck, it’s your conscience. These mostly sound recommendations have come from thousands of events, same as OSHA regulations – good sound logical safe practices based on experiences of the past.
Face it, in today’s sue-thy-neighbor society, if you can even remotely be shown to have known that a part was not to have placed on a boat and you sell it or even if a friend is injured because you chose to save a buck – your dead meat, now and for future insurance considerations.
Obtain the right equipment and sleep at ease that if something happened, you’re clean.
propless

[stressedout]

gstark
By the way, USCG certified Holleys have the same front/rear split bowl as non-marine carbs, so it is incorrect that the fuel level is below gasket sealing surfaces.[/QB]GSTARK,
I was not aware of holley marine carbs used for enclosed engines having the same frt rear split fuel bowls as automotive carbs have, the only ones I know of are the model 4010& 4011 which are true marine carbs that the fuel is below any gasket sealing area.Maybe you could give me some model #'s. Thanks......

[djdtpr]

Boy i only hope thet the law doesnt try to start checking everybodys carbs cause it will put everybody i know on the trailer.But im sure if there is a way that they think they can make money off it they will try it.Most of the carb fires i have seen are due to people who should not even be allowed to touch a tool let alone use one try to do work theirselves and screw up if u dont know what u are doing dont touch it!Pretty simple!Well im sure u guys will bash me for this one but im sick of hearing about rules and regulations set by some fat ass sitting behind a desk that doesnt even know what the hell he is talking about!I run a pair of carbs that sure as hell arent COAST GAURD approved.As for hot crusader i havent seen him say his are better or the same as a MARINE carb ive only seen him give his opinion and options!

[BOFH]

Boy i only hope thet the law doesnt try to start checking everybodys carbs cause it will put everybody i know on the trailer.But im sure if there is a way that they think they can make money off it they will try it.Most of the carb fires i have seen are due to people who should not even be allowed to touch a tool let alone use one try to do work theirselves and screw up if u dont know what u are doing dont touch it!Pretty simple!Well im sure u guys will bash me for this one but im sick of hearing about rules and regulations set by some fat ass sitting behind a desk that doesnt even know what the hell he is talking about! I run a pair of carbs that sure as hell arent COAST GAURD approved. As for hot crusader i havent seen him say his are better or the same as a MARINE carb ive only seen him give his opinion and options! Please go back and read my first post. Screw the law... I drive 80+ on the highway, and have enough speeding tickets to paper my wall. I go to clubs and by fine girls under 21 drinks. The boat blew up! It was an outboard, too. To hell with the law, and to hell with the fines. I like all my parts where they are! One time I had an emergency offshore. My boat was thinking, and all I could think of was my passengers. It was scary, and all that happened is that they got there feet wet. (and I lost a boat) I still felt guilty as hell, and I was found to have done everything right! I don't even want to think about how I would feel if I caused some beautiful girl to be burned over half her body...
The only reason to cheat is to save money. If you are that concerned about money, why did you get into boating in the first place? It sure ain't the cheapest thing around...

[djdtpr]

Cheap i guess u can call me that but when u buy a single MARINE carb for 500.00 that wont even buy 1 of my BG carbs,but i guess that makes me cheap.I can respect your point of view.We should do a poll how many people run marine carbs and how many dont,and how many non marine carbs have caused a fire.just an idea.

[Hotcrusader76]

djdplacecraft:
Cheap i guess u can call me that but when u buy a single MARINE carb for 500.00 that wont even buy 1 of my BG carbs,but i guess that makes me cheap.I can respect your point of view.We should do a poll how many people run marine carbs and how many dont,and how many non marine carbs have caused a fire.just an idea.Or how many people have caused the fire and not the carburetor....

[stressedout]

stressedout:
gstark
By the way, USCG certified Holleys have the same front/rear split bowl as non-marine carbs, so it is incorrect that the fuel level is below gasket sealing surfaces.GSTARK,
I was not aware of holley marine carbs used for enclosed engines having the same frt rear split fuel bowls as automotive carbs have, the only ones I know of are the model 4010& 4011 which are true marine carbs that the fuel is below any gasket sealing area.Maybe you could give me some model #'s. Thanks......[/QB]

[djdtpr]

Thats what im talking about!operater error,see it all the time.Pressure regulator,what pressure regulator!!Or it wont start i think ill keep pumping it!!

[CoastGuardSteve]

I think that everyone here is missing one major key to safety.
Vessel maintenance. This will help to ensure that you catch potential problems before they become fatal.
The "marine rated" components comprise the other half of the equation since they are in place to minimize the chances of disaster.
Combine these two and with a savvy owner who is concerned with safety first, then your worries should be minimal. The savvy owner will always ask his/herself, "What if".
Steve
[ August 16, 2002, 02:31 PM: Message edited by: CoastGuardSteve ]

[jrau]

what about distributers. I am running a car hei. where can i get a sealed hei, or can i seal mine? i don't give a shit about the money, I want it safe. as long as it would be sealed wouldn't it be safe. a stamp or tag doesn't mean anything to me? lyou cant tell me approved parts have never failed. I was in the navy and have seen how much attention our government follows regs. I think a sealed dist. with a carb that does not leak, and some good ventilation through the bottom of the bilge is safe reguardless if it has some tag or not. and as for the holley 4010, and 4011, you might have a spare anchor with one. I had one on a car and fought it for 2 months. finally called holley and they recommended a different carb and refunded me. the tech said they have alot of problems with that line.
[ August 16, 2002, 03:55 PM: Message edited by: jrau ]

[79Hawaiian]

Check it out... The marine DUI distributor! "Flame arrestors are installed on each housing". Looks like the best of both worlds... Both cheap and safe.
http://www.performancedistributors.com/358212-1.jpg (http://www.performancedistributors.com/marinedui.htm)
http://www.performancedistributors.com/marinedui.htm
[ August 16, 2002, 05:18 PM: Message edited by: 79Hawaiian ]

[Snowboat]

What about magnetos?

[1stepcloser]

Hotcrusader76:
You will have to "T" that line into a hose that comes off the baseplate, otherwise add one to the existing baseplate if it has been tapped/plugged.
-TySeems to me that would create a vacuum leak. Plumbing into an existing port from the baseplate would be metered air, allowing negative pressure into the fuel pump housing, which is not sealed, creating the leak. (?) On most newer Holley 4150 & 4160 series'carbs there is a small undrilled boss on the right front of the airhorn just below the mounting flange for the air cleaner. You can see it in the accompanying photo. Look just above and to the left of the vacuum advance port. This is a good spot to drill a small hole and epoxy a short length of brass tube for the fuel pump return. As it is above the throttle blades and the venturis it does not affect the air fuel ratio. (until the diaphragm ruptures!)
http://www.holley.com/HiOctn/ProdLine/Products/FMS/FMSC/g0-80508S.jpg

[Rexone]

1stepcloser's anaylisis seems to make sense to me also with regards to the base plate vac leak vs. airhorn type connection. What's your view on that Ty? (I'm by no means claiming any expertise on this, just curious).... :)

[Hotcrusader76]

Rexone:
1stepcloser's anaylisis seems to make sense to me also with regards to the base plate vac leak vs. airhorn type connection. What's your view on that Ty? (I'm by no means claiming any expertise on this, just curious).... :) Do not drill anything! On a boat there is plenty of tubes sticking out of the baseplate (provided a builder didn't block them off) that you can plumb into. Do not drill into the body or metering block unless you fully understand the vacuum paths fully.
Just plumb the tube into the baseplate, into an area that is near a vacuum ported area (hard to explain in words). This procedure is the same for ALL carbs, but not the 4010 and 4011...that's another story.
-Ty

[Rexone]

Ty, how does going into the base plate "not" create a vacuum leak situation connected into the unsealed fuel pump housing above the diafram? seems to me you'd be suckin air right out the the crankcase through the fuel pump mount. Also it seems if this was an easy method of fuel pump venting all the factories would do it, yet they're all in the flame arrester, above the airhorn :confused:

[Hotcrusader76]

Rexone:
Ty, how does going into the base plate "not" create a vacuum leak situation connected into the unsealed fuel pump housing above the diafram? seems to me you'd be suckin air right out the the crankcase through the fuel pump mount. Also it seems if this was an easy method of fuel pump venting all the factories would do it, yet they're all in the flame arrester, above the airhorn :confused: Remember that the engine is sucking the air, not the fuel pump. If you were real worried you could attach a one way valve type of deal, but this is not crankcase pressure verse engine vacuum.

[Rexone]

It just seems logical to me that connecting what essentially is a vacuum line from the base plate of the carb to any open source (in this case the fuel pump housing above the diafram which isn't air tight) will just suck air into the carb base(vacuum leak). It would be the same as just attaching that hose to the base plate and connecting it to nothing, letting it hang off the side of the engine...it's gonna suck air, thus affecting the air fuel ratio adversely and affect manifold vacuum. I'm not even concerned with crankcase pressure which would be insignificant in this case, it's not even a factor.

[Hotcrusader76]

Rexone:
It just seems logical to me that connecting what essentially is a vacuum line from the base plate of the carb to any open source (in this case the fuel pump housing above the diafram which isn't air tight) will just suck air into the carb base(vacuum leak). It would be the same as just attaching that hose to the base plate and connecting it to nothing, letting it hang off the side of the engine...it's gonna suck air, thus affecting the air fuel ratio adversely and affect manifold vacuum. I'm not even concerned with crankcase pressure which would be insignificant in this case, it's not even a factor.Correct me if I am wrong, but didn't you state that someone was looking for a place to tap their fuel pump wheep hole into? Then that wouldn't be an open source....until it leaks. Right?
:)

[Rexone]

Ty, I just went out and checked a fuel pump. I was under the assumption that the weep hole was open through the pump mount...it isn't. I stand corrected. At least it isn't on the Carter pump I checked.
I guess my only concern would be how applying manifold vacuum to the top of the fuel pump diafram might affect the function of the fuel pump.
It just seems to me that if this was an acceptable method of venting the fuel pump all the factories would do it, because it's easy. Yet none of them do, they all use the flame arrester above the air horn which is subject to air flow induced vacuum, but not manifold vacuum.
I'm just probing for that answer now I guess. Thanks for your input.

[Rexone]

One other thought is that applying manifold vacuum to the fuel pump diafram might cause a partially weakened rubber diafram to actually start leaking where it wouldn't do so otherwise without the vacuum sucking on it.

[Hotcrusader76]

Rexone:
One other thought is that applying manifold vacuum to the fuel pump diafram might cause a partially weakened rubber diafram to actually start leaking where it wouldn't do so otherwise without the vacuum sucking on it.I suppose your correct in that the air horn, if applicable, would be the best place to mount it. But then again those of use who run tunnel rams, with giant oversized scoops rarely run Marine grade pumps either.
Your correct though. I checked with a few pics of some factory installs I have done and that is correct. The fuel vent was tapped into the lesser of the vacuum drawn ports.
Wheew...Thanks Mike...I knew you and I could figure this one out...LOL
-Ty

[Jungle Boy]

Why would you not be able to plumb the fuel pump diaphram vent back to your fuel tank with a clear hose that could be monitored when you first put the boat in the water and you are doing a visual on the engine and hoses?

[Hotcrusader76]

Jungle Boy:
Why would you not be able to plumb the fuel pump diaphram vent back to your fuel tank with a clear hose that could be monitored when you first put the boat in the water and you are doing a visual on the engine and hoses?Even better idea I think. But the fuel vapor is the concern, and getting it back to a source that can burn it is the better approach.
Or even a puke tank! But fuel vapor is very volatile, so getting it down the engine is the best.

[Boatcop]

Why would you not be able to plumb the fuel pump diaphram vent back to your fuel tank with a clear hose that could be monitored when you first put the boat in the water and you are doing a visual on the engine and hoses? We're back to square one. Any fuel hose leading to or from the tank needs to be Marine Type USCG Approved, and equipped with proper one way, back-flow prevention, anti-syphon valves. There is no "clear" hose which meets those specifications.
I think there's a reason that the typical design has the fuel leak line coming from the fuel pump to the flame arrestor. Running it from a vacuum port on the carb would have an adverse effect on the pump operation, and might result in un-expected engine acceleration in critical situations in case of diaphram failure. Fuel into the carb throat wouldn't cause as responsive or immediate engine reaction as fuel introduced directly into throttle body through venturi vacuum.
I'm sure that USCG, NMMA, and ABYC Engineers looked at every possible configuration to minimize risks of introducing incidental fuel into the bilges, and this system is what they came up with.
Best solution? Cap off the mount and install an electric fuel pump.

[Rexone]

Ty, A puke tank would defeat the whole purpose introducing fuel vapor back into the air just like the fuel pump would without a hose connected, even though it would be in a different location...no advantage.
The positive to the flame arrester method is also that there is "slight" neg pressure created by air flow which tends to suck any fuel leakage that might be present back into the carb rather than relying on just flow under zero pressure.
Like Alan says, I'm sure many thousands of dollars have been spent designing the best method of accomplishing how to handle this fuel problem by those agencies so we're beating a dead horse here trying to circumvent their really very simple method of dumping it back into the flame arrester which works very efficiently and solves the problem. Just my .02

[Hotcrusader76]

Rexone:
Ty, A puke tank would defeat the whole purpose introducing fuel vapor back into the air just like the fuel pump would without a hose connected, even though it would be in a different location...no advantage.
The positive to the flame arrester method is also that there is "slight" neg pressure created by air flow which tends to suck any fuel leakage that might be present back into the carb rather than relying on just flow under zero pressure.
Like Alan says, I'm sure many thousands of dollars have been spent designing the best method of accomplishing how to handle this fuel problem by those agencies so we're beating a dead horse here trying to circumvent their really very simple method of dumping it back into the flame arrester which works very efficiently and solves the problem. Just my .02I completely agree with you Mike! Why re-invent the wheel?

[1stepcloser]

The Carter carbs that Mercruiser used to run (prior to fuel injection) all had the fuel pump overflow routed to a port that ran into the venturi. This is the ideal spot for raw fuel to go. I would think that if it is plumbed into the bottom of the air cleaner housing fuel could puddle, and if allowed to continue, eventually leak past the air filter onto the manifold. Even if it stayed contained within the air cleaner, it would still not be a safe situation. This is just my thoughts though...
[ August 19, 2002, 09:20 AM: Message edited by: 1stepcloser ]