Fuel level sending unit "vent hose" routing question

[CallMeHoovy]

Hello everyone,

I am working on my 1985 GS450GA and I am wondering where to route the hose that comes out of the fuel sending unit. I cannot for the life of me remember if it just vents to air or if its meant for a specific carb hookup. Image of the offending barb attached directly. In checking the diagram I can see it is labeled vent hose, but it is not labeled if it is direct or recaptured in some way like the crankcase breather. trying to make my first motorcycle as close to OEM as 1985 will let me.

[CallMeHoovy]

Peep the fire extinguisher in the background. I'm 26 years old, don't make excuses, buy one.

[OkamiS]

If I remember correctly it goes to the fuel petcock. I just recently took the cover off my sending unit and that's where that hose went on my cover.

[1978GS750E]

All the bikes I've ever seen, that hose is vented to air. It is to let any fuel from a leaking sending unit drain. Of couse, I haven't seen everything, yet!

[Rijko]

If I remember correctly it goes to the fuel petcock. I just recently took the cover off my sending unit and that's where that hose went on my cover.

someone hooked that up wrong, let me guess now your bike only runs on PRI ?

[Rich82GS750TZ]

If I remember correctly it goes to the fuel petcock. I just recently took the cover off my sending unit and that's where that hose went on my cover.

No. No. No. No. No. !!!!

The line that comes off the fuel sending unit is NOT a vent. It does NOT go to the petcock. It is a drain tube. A drain tube that will remain dry for its entire life until and only until/if the gasket sealing the sending unit to the fuel tank leaks. It should be routed over the carbs and down behind the engine, off the the right side where there is typically a chase for drain tubes to run out to the ground, so as not to be exactly in front of the rear tire. Some other drain tubes may also be routed there: tube carrying expended crankcase oil vapor and over-oiled air filters from the airbox; and drain tube from non-sealed lead-acid batteries.

[Nessism]

someone hooked that up wrong, let me guess now your bike only runs on PRI ?

LOL!

Edit: Rich's post came in while I was typing, and explains all...

The sending unit cover is a funnel, to catch any fuel that may leak past the sending unit seal. The hose attached to the nipple needs to route to the ground, away from the rear wheel, please.

[CallMeHoovy]

Holy S*** I hopped on a game of fallout 3 thinking there's no way Ill get a response with so few people online. You guys are the best. Thank you for the explanations

[Rich82GS750TZ]

Well, you are 26. And we’re, um….not.

Welcome to the forum.

[rphillips]

Welcome Hoovy, just say'in you're not the first to wonder about that hose... Though I don't remember anybody with a "REPAIR MANUAL" asking about it. I not selling repair manuals, just letting you know they sure are handy to have around.

[salty_monk]

The metal bit on the tank is like a cup, any leak would spill there and then drain through that hose…

[OkamiS]

No. No. No. No. No. !!!!

The line that comes off the fuel sending unit is NOT a vent. It does NOT go to the petcock. It is a drain tube. A drain tube that will remain dry for its entire life until and only until/if the gasket sealing the sending unit to the fuel tank leaks. It should be routed over the carbs and down behind the engine, off the the right side where there is typically a chase for drain tubes to run out to the ground, so as not to be exactly in front of the rear tire. Some other drain tubes may also be routed there: tube carrying expended crankcase oil vapor and over-oiled air filters from the airbox; and drain tube from non-sealed lead-acid batteries.

Well that might explain a few things! I'm glad I did decide to comment on this thread. That is probably the reason the previous owner said the gas tank was leaking. ROFL I can only imagine fuel shooting up that hose to the fuel sending unit cover and running out the top and down the inside of the tank. They said the tank had a leak, but when I examined it, I didn't find any possible spots it would leak from. If anyone could point me in the right direction on how this hose should be routed, I'd greatly appreciate it!

[CallMeHoovy]

Welcome Hoovy, just say'in you're not the first to wonder about that hose... Though I don't remember anybody with a "REPAIR MANUAL" asking about it. I not selling repair manuals, just letting you know they sure are handy to have around.

parts diagrams be like " hose-vent" and refuse to explain further

[rphillips]

Ken, it's not real critical as long as it drains under the bike preferably with no swags that can hold any gas that will probably never leak anyway. Usually along the along the frame to near the air box then sideways to a frame down tube to under the bile, hopefully not straight in front of the rear tire... Many times I've thought the parts diagrams could use better wording. For me this is a drain hose, just something we got to deal with. Glad it's figured out, that's the main thing.