Steve Snider

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.

Cmoney

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.

RumRunner

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.

rbtnt

Thanks Doug

kevinr

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.

rbtnt

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"

Kidnova

Thanks RumRunner post 36 makes it much more clear.

SledgeHammer

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.

Sadist

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...

kevinr

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!