Marine Carb or Not
 

I am in the process having two 540's built. My engine builder and I were talking today and he suggested maybe using a Quick Fuel Technology Professional Series carburetor, instead of the 1050 Holley marine carb that we were supposed to use.
Any thoughts on that?
I told him I would like to stick with the holley Marine carbs, are there any advantages or disadvantages?

Re: Marine Carb or Not
 

Let the coast guard find a non marine carb,,, or have an incident and have your ins company find a non marine carb and there will be issues,,,just not worth it to me. :(

Re: Marine Carb or Not
 

Theres a good reason for marine carbs and the cost difference isnt worht dealing with, ecspecially gettin tied up if u get sued and ur insurance wont cover it.................

Re: Marine Carb or Not
 

I would not recommend using anything other than a marine carb. Call Dean or Brad @ Nickerson performance. They will set you up right the first time with the right carb.

Re: Marine Carb or Not
 

As a marine surveyor I would highly recommend not using a non-marine carb. The overflow tubes on the top of the marine carb are bent 180 degrees to return fuel to the carb instead of blowing it straight up like a automotive application does. There could also be a issue if the carb has a electric choke that does not meet marine standards for ignition protection. My two cents.

Re: Marine Carb or Not
 

Here here to all of the above. Hope you take the advice and don't risk lives over it.

Re: Marine Carb or Not
 

So can 4150s or dominators be converted to marine carbs or is this not feasible?

Re: Marine Carb or Not
 

I had the J-tubes installed on my 1050 blower carb. Had the standard shafts though. At what point will it be considered a CG approved carb?

Re: Marine Carb or Not
 

Aren't the shafts sealed to the main body on marine carbs? I would think they would have to be to prevent fuel from leaking out if the carb was to flood through the "J" vent tubes.

Re: Marine Carb or Not
 

I have bought J tubes for some other guys, but as you said, that is not everything that makes it a marine carb.

Re: Marine Carb or Not
 

Steve Snider nailed it.

I am an insurance claims adjuster {shhhh....}. If you have a loss that is related to non CG compliant stuff on your boat {including the carb}, you will be SOL regarding coverage. i.e. they won't pay ya.

I sent the Holly 850 from my ZZ502/502 to Nickerson's to have it marinized. It came back with J tubes installed, elec. choke gone, and numerous other mods. I bolted it on and the ZZ runs like a raped ape. Cold starts are better than ever. Checked plug color and they look good.

Carb is now CG good, ins. co. good, and performs good. All I needed to do was to adjust the idle/throttle stop screw.

Re: Marine Carb or Not
 

As mentioned before there is no good reason not to run a marine carburetor on a pleasure boat. As far as converting the carburetor goes that can be a very grey area depending upon how in depth they want to get with you. There are changes to the way the throttle shafts are installed, and manufactured on a marine carbruetor. At this time there are not any "USCG Leagal" carburetors. To pass the inspection the manufacture of the carburetor has to prove that they tested the product to meet the USCG requirements when it was designed. If you have someone modify the carburetor to "marinize" it other than the manufacture of it, you might be in a very grey area. If the insurance company checks the list number of the carburetor, and the manufacture explains that it is an automotive carburetor, who is going to be responsible?

Re: Marine Carb or Not
 

Anyone have a Holley Marine "J" tube part number? Can't seem to find one.

Re: Marine Carb or Not
 

I bought them from CP Performance before. I did wonder why they stocked them.

Re: Marine Carb or Not
 

would not recommend using a carb at all

Roby

Re: Marine Carb or Not
 

If you have the money to build 2 540's How can you consider going cheap on carbs? I would walk out the door in a hurry from ANY builder who suggests outherwise. They have NO idea about MARINE engines if they suggest an auto carb.....BG makes awesome marine carbs.....

BH

Re: Marine Carb or Not
 

I just ordered a Sea Demon today.. Pricewise they really arent that bad..

How much did Nickerson get to mod the Holley??? I have a canidate for that on one of the boats...

Re: Marine Carb or Not
 

Scott B.,
Including shipping, the cost was almost as much as it would be to purchace a new marine carb.

My Holly came with the ZZ502. Thought of selling it, and then buying a new marine carb. But, I couldn't find anyone willing pay enough to make it worth while. So off to Nickerson's it went.

Along with the carb, Nickerson's requested complete engine specs, plus boat description and weight. They dialed it in perfectly. I'm glad I sent it to them instead of buying an off the shelf carb.

Re: Marine Carb or Not
 

Thanks.. I have a 750 that works great on one of my boats, but I wwould like it marinized.. I'll do some budgeting!!

Re: Marine Carb or Not
 

Scott,

IF you have any tuning questions on the new carb just let me know.

Re: Marine Carb or Not
 

As a followup. Am I the only one who encounters leaking pump diaphrams on Holleys. I've seen dozens and 1 fire due to the leak. Just wondering why a potentially leak prone design is CG approved.
Gary

Re: Marine Carb or Not
 

When people want to use Non-marine parts on a boat, I ask them: " What is you life worth, but more importantly what is your family's life worth." Take it from someone who has seen a boat explode and kill a family on vacation because the boat owner used an auto HEI distributor. ITS NOT WORTH IT!!!!

Chris

Re: Marine Carb or Not
 

When I discussed the mods with Nickerson's they mentioned that throttle shafts would be reworked, power valve changed, J tubes added, choke removed, re-jetted, plus a chitt load of other mods. I don't know the proper technical terminology {carb/engine knowlege challenged}. But, I figured that I was doing the right thing at the time.

My primary concern was with the lack of J tubes, which are now there. But after reading your post, I wonder if I'm ok with this carb.

Re: Marine Carb or Not
 

First of all, I never said it was a money issue. I asked if there were any advantages or disadvantages to using a marine Dominator vs a Quick Fuel Tech. My builder explained the differences to me, and gave me the choice. I didn't see how it would benefit me, so I chose to stick with the Dominator. But now that I know that he doesn't "have NO idea about MARINE engines" I guess I can't trust him.

I appreciate most of the replies. .
Thanks
C

Re: Marine Carb or Not
 

This sounds like a real gray area if there is not an USCG approved carb.

Re: Marine Carb or Not
 

So the question remains, does reworked throttle shafts, added J-tubes, removel of electric choke make a marine carb? According to RumRunner, the only thing that will qualify as one, is the ID numbers, regardless that an auto carb has been 100% modified to as -same -as an 'original' marine carb, which is in itself still not classified as USCG approved.

Re: Marine Carb or Not
 

[QUOTE= At this time there are not any "USCG Leagal" carburetors.

If the insurance company checks the list number of the carburetor, and the manufacture explains that it is an automotive carburetor, who is going to be responsible?[/QUOTE]


Not arguing RumRunner, just trying to get some clarification on this. What about the BG carbs, or other manufactures that advertize "marine" carbs? Do they qualify or are they leagal/approved for marine use or not? You say there are none that are CG "legal". Does that also mean there are none that are CG "approved"? Yikes...that's a grey area! If that's the case, there are a lot of boat owners out there that are in potentially deep sh&*t.

Re: Marine Carb or Not
 

I have also heard that the braided fuel line is not USCG approved. Does this mean that if you have a carb(s), marine or not, and/or braided fuel line, you are not Coast Guard approved?

Re: Marine Carb or Not
 

Sorry If I spoke out of turn......But from your post I got that he "gave you the choice" and didn't explain how it would "benefit" you. The fact that he would not RECOMMEND strongly that you go with a carb designed and INTENDED for marine use I find VERY unnerving....Not trying to be a smart ass but does he recomend automotive starters and alternators also? Again please excuse me If I spoke out of turn...

BH

Re: Marine Carb or Not
 

Thanks Doug. I don't expect any issues, from what folks here tell me they are a breeze to work with. I'm looking forward to it!!

Re: Marine Carb or Not
 

As a marine surveyor inspecting a marine inboard engine I look for the "J" tubes and a fuel line marked USCG approved. The most critical fuel line is the fuel pump to carb hose. USCG approval is determined by burn time. Aeroquip fuel lines in my opinion should be acceptable. I have to admit that I have Aeroquip fuel lines and fittings on my 540's. I believe the problem is the USCG regs are not often updated.

Re: Marine Carb or Not
 

I asked him about the automotive starters and alts, he was dead set against using them in boats. He suggested using the Quick Fuel because he thinks they come tuned much closer from the factory then the Dominator. To me it wasn't worth taking the chance, he didn't seem to think it would be a big deal. Trust me I was surprised too, thats why I started this post.

Re: Marine Carb or Not
 

Not arguing RumRunner, just trying to get some clarification on this. What about the BG carbs, or other manufactures that advertize "marine" carbs? Do they qualify or are they leagal/approved for marine use or not? You say there are none that are CG "legal". Does that also mean there are none that are CG "approved"? Yikes...that's a grey area! If that's the case, there are a lot of boat owners out there that are in potentially deep sh&*t.[/QUOTE]

The USCG does not "approve, accept, or legalize" carburetors. They give manufactures guidelines that they must pass within. When we design a "Marine" Carburetor for use on a please boat we test it to make sure it passes these requirerments. This means that if you have any type of problem with the USCG, or your insurance company, we can verify that, that carburetors was designed to pass the guidelines. We can then inspect it for them to make sure there have not been any modifications from stock.

I hope that clarifies it.

Re: Marine Carb or Not
 

Thanks Doug

Re: Marine Carb or Not
 

I agree with your engine builder,anytime you get a custom built carb,that carb is dialed in for its own body & throttle plates by way of the airbleed's & metering plates. The engine's will be closer tuned.
As far as marine carb, I cant speak for small square flange Holley's,but I know Dominators and there is no diference between them accept for the J bend bowl vents (aleast thats what Holley said) And for all these guy's saying a Dominator is a automotive carb!!! There is nothing automotive about it, It was built for racing!!!!

Hell I love them , thats all I use , I even love King Demon's.
But if you feel uneasy about the straight vent's , get Quik fuel to install J tubes,or you can buy them from holley and install them yourself.

But you got to ask yourself what does the J tubes really do. In the case of floats getting stuck or a needle & seat not sealing ,the bowl would fill up with fuel causing it to go out the tube. J tubes would direct down the venturi instead of getting caught by air traveling across the top of the carb mixing together with fuel creating a atomized fuel rich enviroment in your engine compartment. There theory , ca boom !!!!! It is the same reason there is a tube coming out of a mech. fuel pump , intended to go to the spark arrester incase of a diaphram failure.

Re: Marine Carb or Not
 

Here is part of an marine carb article from Powerboat. The also talked about the shafts in another paragraph.


"Do not try to convert a standard nonmarine carburetor to a marine carburetor by adding "J" tubes. Some people think this is an acceptable practice. It is not. Because of their shape, the "J" tubes are affected by the air velocity passing around them at the top of the carburetor venturi. The result is lower atmospheric pressure in the fuel bowls. The marine version carburetors are calibrated differently to compensate for the effect of the "J" tube"

Re: Marine Carb or Not
 

Thanks RumRunner post 36 makes it much more clear.

Re: Marine Carb or Not
 

Can anyone actually quote the exclusion in their policy that says there is no coverage if you use non USCG equipment? I have checked mine and there is no such exclusion. If anyone can quote the exclusion from their policy, name the company as well. I am not advocating using non USCG equipment, but I have seen these comments frequently about what insurance companies won't cover. If it is not specifically excluded, then it is covered.

Re: Marine Carb or Not
 

PCM part number RN0127 available special order from a Crusader / PCM dealer (ski boat guys... ski nautique and the like) is the holley "j" vent tube, I have 4 on my shelf, they're cheap as hell (like a couple of bucks).
But like other posters have stated, there's more to vent tubes in a marine carburetor.. however, not much more...
The J vent tubes alone will pass an inspection.. But skin grafts are REAL expensive...

Re: Marine Carb or Not
 

If that is the case,couldnt the carb builder install the j tubes and then wet flow the carb body to compensate for the dfferent signal coming across the ai bleeds. And for that matter I have adjusted the airbleeds on the Dyno as directed by the custom carb builder because there are things to factor in (type of spark arrestor,how much air comes across the top of the engine ect....)Nothing is set in stone!