1980 GS 550 fuel lines

[newt113]

I'm rebuilding a 1980 GS 550ET. I am having problems figuring out how the fuel lines are supposed to be configured after they exit the petcock and before they enter the carbs. I'm not sure which ports are for vacuum, which lines are for fuel delivery, what are any other lines that might be. Is there one direct fuel line into the carbs or does the line divide into three delivery hoses into the carbs? Does anyone have a schematic of how the heck these fuel lines look when they are hooked up right. Thanks very much, and I can be reached at JBeneauMetz@gmail.com or newt113@hotmail.com Have a great day.

Ben

[80GS1000]

The big port going from your petcock is the fuel line. It hooks up into the large hose between your #2 and #3 carbs. The smaller port one is the vacuum line. It hooks up into a smaller tube which connects at the back of your #2 carb.

[newt113]

but what about?...

Thanks for the response, I think that I understand a little bit better. what about the 2 other tubes that are entering the carbs on the same side as the middle fuel intake line. what do they do and are they supposed to have anything attached to them?

[txironhead]

Those are vent lines, they should have tubes attached that either attach to the airbox or just vent into the atmosphere. If you're running pod filters, it's recommended to cap those tubes off to prevent siphoning.

[Nessism]

Those are vent lines, they should have tubes attached that either attach to the airbox or just vent into the atmosphere. If you're running pod filters, it's recommended to cap those tubes off to prevent siphoning.

I'm pretty sure you don't want to cap the vents or fuel won't flow properly - vacuum will be created.

[Steve]

Those are vent lines, they should have tubes attached that either attach to the airbox or just vent into the atmosphere. If you're running pod filters, it's recommended to cap those tubes off to prevent siphoning.

True they are vent lines and should remain open.

If you are using a stock airbox, the hoses are probably routed over the airbox and under the seat.
You might find a loop on top of the airbox that will hold the hoses in place.

If you are using individual pod filters on the carbs, remove the hoses. Leave the vents open, the carb bowls still need to breathe. :shock:


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[newt113]

Thanks

Hey thanks for all of the replies fellas. Your information was really helpful. I'm running two pod filters on the bike from K&N so there will just be vent lines coming out of the carbuerator (spelling). is the consensus that I should not put hoses on these vents and leave them just a bare nipple coming out of the carbs?

[Steve]

That would be correct, bare vent nipple, no hose. I don't know if there is a preferred position, but I think I would point them down.


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[txironhead]

There was a rather lengthy thread here about how running the vent tubes with pods caused a siphoning condition. The recommendation was to cap the tubes. I haven't had a chance to test this on my bike as I'm still trying to get it running. Maybe running the tubes to where air cannot flow over the ends at speed?

Are the vents are there simply to allow fuel gasses to exit the system without building up pressure?