more brawn then brains

[labrador]

This weekend I was going to change the little filter in the fuel line between the fuel pump and the carb. Well I twisted so hard I screwed up the fuel line and have to replace it.Not wanting to go and pay a boat buck for a fuel line from the mfg. I went to a tractor supply house and got a pc. of copper tube with the correct fittings and and had it flaired and bent. The original line was steel tube. Is there any reason why this 17.50 pc. of copper with the correct fittings is not suitable? Being a gas engine I want to make sure this is ok.

 

[MikeP]

That line must be replaced with the same material as oem - steel. It is steel because the engine vibration will work harden the copper and cause it to fracture eventually. Steel is always used when a "hard" line is employed in that application. You could use rubber fuel hose - it won't be bothered by the vibration but hard line is used is to ensure engine heat does not damage the hose since the line frequently runs near very hot components.

 

[spartonboat1]

ditto, brake lines and fuel lines, Cu need not apply...not a valid application...

 

[67hat34c]

be sure to use marine grade fuel hose, i put it side by side with automotive and it is way thicker. I replaced the steel fuel supply between the fuel pump and the carb on my gen with fuel hose, keept it isolated from the block and made sure nothing could ever chafe it.

Interesting about the copper changing properties, learn something new every day. Hatteras used copper fuel lines from the tanks, not sure where they ended originaly as mine has been altered several times. we have original copper on the tank but now transition to hose before it leaves the forward end of the tank.

 

[Maynard Rupp]

be sure to use marine grade fuel hose, i put it side by side with automotive and it is way thicker. I replaced the steel fuel supply between the fuel pump and the carb on my gen with fuel hose, keept it isolated from the block and made sure nothing could ever chafe it.

Interesting about the copper changing properties, learn something new every day. Hatteras used copper fuel lines from the tanks, not sure where they ended originaly as mine has been altered several times. we have original copper on the tank but now transition to hose before it leaves the forward end of the tank.

They did use copper hose for engine fuel, but they stopped the copper on a shelf far from the vibration and finished with a super aircraft grade blue hose. That hose absorbs the vibrations. Believe me, Hat did all that stuff almost too right. Never use copper or aluminum tubing in a vibrating environement. The problem is called work hardning. It is the same reason you can break a coathanger with repeated bending.

 

[Boatsb]

The line from the fuel pump to the carb MUST BE STEEL!!!!!!!!! Copper and hose will not meet the CG requirements. That is the high pressure side and legally must be the steel.

What engine is it for? 350 Block? 454? I got 2 new crusader ones for my 350 chevy blocks deliverd for less than $60.00. Its not worth the few dollars that you save as copper can leak and ruin your day permanently

 

[67hat34c]

good point scott, anything done must meet uscg requirements, could void your insurance if something happens. I will have to check into this. Reason i removed steelone because it had a crappy in line filter after the fuel pump. did not see need for this as new fuel pump has a built in one and there is large can filter on the bulkhead. Just wanted to get rid of extra joints.

 

[MikeP]

The line from the fuel pump to the carb MUST BE STEEL!!!!!!!!! Copper and hose will not meet the CG requirements.

Well I'll be...

I always thought that was true but I got curious as part of this thread and tried to find the USCG requirement. I readily admit I might have missed it but I couldn't find anything in the USCG regs that actually state that. The only thing I could find was the a statement that IF hose is used, it must meet the applicable requirements for fuel hose. Apparently there is no requirement to use metallic line anywhere! Ouch!

The regs I found are 183.583, 183.540. and 183.542. Again, I may have missed the one we are talking about. If so, please point me to the proper reg.

I also looked at some boat-building sites that quoted the USCG requirments: They talked about using hose in the entire system and further stated that if you wanted to use metal you could, noting that some manufacturers use it from the fuel pump to carb.

Basically, it looks to me like almost the opposite of what I have always "known" to be correct re fuel lines on the engine.

Again, I reserve the right to be shown that I misread all this...

Here's a site that has a lot of the info:
http://www.uscgboating.org/safety/boatbuilder/fuel/fuel.htm

 

[67hat34c]

Come to think of it all the fuel lines in my jet ski's are rubber hose, including the high pressure ones on the DI model which has a 150psi fuel pump. I would have to guess they are coast guard regulated as well.

 

[Boatsb]

Fuel lines on outboards can be rubber too. Not for inboards though. below decks and in a vessel is differant than an PWC or outboard.

 

[thoward]

My understanding is A1 rated marine fuel hose can be used anywhere in the system.

 

[labrador]

OK OK I get the message. The fuel line is being replaced with oem parts. Glad I started this thread as I may have become chum sometime down the road. Thanks to all!

 

[MikeP]

I'm glad you started it too - it made me look at the actual regs instead of being absolutely sure of the wrong information!