Strange 1988 5.7 fuel line question

[patchkit123]

I was wondering if anyone could tell me if the very small (3/16 or so) yellow line going from the carb to the fuel pump is a special type of line? It is not the fuel supply line. I use a yellow fuel line in my bizz that is called tygon fuel line. It is the same size and fuel safe. I have a freind who tells me it is a very special line that CHANGES COLOR if it every gets fuel it and that tells you that you have a bad fuel pump or overfilled carb bowl from leaky needle and seat, bad float or wrong float level. He also has three nice boats. He said he was told that by a merc dealer at the Lake of the Ozarks. I called a local dealer with a master merc tech on staff and they said it was nothing special. I would guess it is see thru so you can see if gas is getting in it or it would be black or metal like other fuel line. The tygon changes color a little after fuel sits in it. I'm not trying to get away with a cheap part on my boat but I have a hundred feet or so of the tygon fuel line in stock and that line(merc part # 32-7381567) cost 19.21+ shipping and tax for about 43 inches I only need half about of that. At this stage of the game every dime counts but don't want to risk anything over $20.00. I know I worry about details a little too much at times but would like to do it right without breaking the bank. Thank you very much.

 

[J Levine]

The purpose of the line is to route any fuel that would make its way through the diaphram of the fuel pump to the engine to be burned. The line is clear so you can see inside of it. If you see fuel in this hose you know the fuel pump is going bad. It keeps a broken fuel pump from flooding the engine crankcase with fuel and exploding.

 

[patchkit123]

Thank you. I have seen that happen on a SB chevy before. Fuel started coming out of the vent hole in the pump body. I do have a new pump and will be replacing it since the engine is out and has about 20 years/550 hours on it. I just wasn't sure about the color changing thing. Sounded strange to me. Thanks again.

 

[patchkit123]

Just to be clear that the dealer I called did say it needed to be see thru and fuel safe. Just not majical color changing type. So they didn't give me any bad info. I think my yellow stuff will be fine. Its for 2 cycles and allows you to see fuel prime thru the line when you hit the primer bulb.