Gas line question...

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carver 2557

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I had to remove the carb on my 5.7 Mercruiser and in the process, the gas line from the fuel pump to the carb was damaged beyond re-use...Now do I have to replace this with a steel line or can I use a rubber or whatever material gas approved line with clamps?...
 
I would use a metal line with threaded brass fittings at the ends. There is too much pressure there not to. That's why it's there. I use rubber gas line from the tank to the pump. I tried that with a truck I once had, rubber line from pump to carb. It came off from the pressure and I almost had a fire.
 
carbs don't have high pressure that fuel injected engines have. in my boat i used marine grade fuel injection hose from the pump to the carb w/ stainless clamps. Never had any problems with my setup!
 
The fuel pump to carb line has been replaced with a CG approved Flex line with flare fittings on the ends. Any parts store should be able to give it to you in the length that you need. Makes it easier to clean the inline carb filter.
 
I've seen Flex lines in marine grade steel mesh covered 25" and 31" lengths that are made for just this purpose.
In a jam you could always make two nipples out of a 10" rigid piece of fuel line. Just get a tubing cutter and cut each end to length (about 3" or so). Attach one nipple to the carb, and the other to the fuel pump. Use rubber 3/8" marine fuel line in between the two nipples you made, and double clamp each end to the nipples with stainless steel hose clamps.
I just had to make a piece up to go between my fuel pump and fuel filter. The ready made flex lines were way too long for the spot I needed to put them in. I ordered the replacement pre bent rigid line, but didn't want to not be able to use the boat while I'm waiting for it to arrive.
The set up with the nipples, rubber line and stainless clamps will last for years if I needed it to, but I'll still replace it with the pre bent rigid when it gets here next week because it's available. If it wasn't available I wouldn't hesitate to leave the set up on there forever.
You can get the rigid fuel line at any good auto parts store. It comes in different lengths. It's too thick to safely bend much though. 10" is usually about the shortest they sell it, and all you need. The fittings on each end will be flare type and will thread right in to the carb and pump.
You can get the stainless steel hose clamps at ACE Hardware, or any good hardware store. The marine fuel line can usually be had by the foot at a marine supply store.
FYI - The fuel lines going in to the Quadrajets are easy to twist up when removing or installing them. Sometimes there is just no avoiding it. I have a very thin Snap-On 1" open end wrench that I use to hold the internal fuel filter housing in tight with while I back the fuel line out of it. I usually soak the line really well with PB blaster before I try to back it out.
 
Check boatfix.com for the parts you need. You probably won't be able to beat the prices. Only CG approved parts should be used to help prevent having a leak/fire.
 
quote:
Originally posted by JVM225

FYI - The fuel lines going in to the Quadrajets are easy to twist up when removing or installing them. Sometimes there is just no avoiding it. I have a very thin Snap-On 1" open end wrench that I use to hold the internal fuel filter housing in tight with while I back the fuel line out of it. I usually soak the line really well with PB blaster before I try to back it out.

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Thats exactly what happened to me...I was trying to be careful, but it wasnt moving, so brute force and a bit of temper,,,well maybe lots of temper...anyways I got it off, but the line twisted...
Thats why I am asking about the different set-up to avoid future problems...
 
you can use marine grade rubber fuel line as long as you use the correct fittings and double clamp we do it now to cut down on heating the fuel as its a problem on charter boats idling 8-10 hrs a day
 
quote:
Originally posted by tugboat kevin

you can use marine grade rubber fuel line as long as you use the correct fittings and double clamp we do it now to cut down on heating the fuel as its a problem on charter boats idling 8-10 hrs a day

Click to expand...


That's how I did mine, and it works fine.
 
I just spoke with the shop that is rebuilding my carb and though that I would pass along what he told me about the gas line...There is no problem going to a rubber line, but, Keep in mind that this is Canada and I don’t know if it applies in the USA, but, If the steel line is replaced with a rubber line and you have a fire, your insurance will not cover it as you have not stuck with a factory gas line...Take it for what it's worth, but might be something to check out before a problem arises...
 
you are still in compliance by using coast guard approved hose and double clamps some pre fuel injected oem's used it you are really only updating to be able to run the scamathol we are forced to run and deal with
 
So I had the carb rebuilt at a cost of 260 bucks...Hard to find a mechanic that will rebuild a 4 bbl carb, but I found one that works on high performance engines, and he was surprised that my boat even ran with the shape the carb was in...
I went to the local auto parts store to get some fittings to hook up the gas line...hooked it all up and fired the engine up..purred like a kitten, but I noticed a small gas leak from one of the fittings, so to be safer that sorry,I shut it down and I ordered the proper line from Mercruiser...
 
I recently R+Rd the carb because I had to have it rebuilt...and what I did not to bugger up the fittings was to use a flare wrench on the small nut that screws into the filter housing, I actually had to remove the thermostat housing to get clearance for the wrench..
 
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