[cldryder]

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My 88 has a rigid plastic tube that passes thru the area exposed when you open the door covering the fuel cap. The tube has a "T" just left of center that, on my bike at least, has nothing connected to it. The pic in the manual shows a hose connected to the "T" but there were no loose hoses in the area of the "T". I was not able to detect any vacuum in the line.

A friends 1989 did not have this plastic tube.

Does anyone know what this particular vacuum line (assuming it is a vacuum line) is for?
thanks Mark in MN

 

[twisty]

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cldryder wrote:

My 88 has a rigid plastic tube that passes thru the area exposed when you open the door covering the fuel cap. The tube has a "T" just left of center that, on my bike at least, has nothing connected to it. The pic in the manual shows a hose connected to the "T" but there were no loose hoses in the area of the "T". I was not able to detect any vacuum in the line.

A friends 1989 did not have this plastic tube.

Does anyone know what this particular vacuum line (assuming it is a vacuum line) is for?
thanks Mark in MN

Mark, I'm not familiar with the 88's venting system but you could be looking at the fuel catch drain, those are usually there to allow any fuel spilled at fuel fill-up to flow out of the catch tray & to the ground rearward of the bike's engine. Check it out & maybe you will have to add a hose there to carry any spilled fuel away from the hot engine..

Twisty

 

[philcsand]

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It could also be part of the PCV system... THere is a seperator just forward of my bike's tank (1200) that the hose enters, and when it exits, it heads down to the con-tank near the left driver's peg.

 

[DJ]

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I don't know what that valve does, but I do know that some 1500s have a tube attached and most don't. I suppose it depends on year etc.

 

[cldryder]

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thx for replies. I'll figure it out (I hope) this winter when I rebuild the carbs.

 

[Tonys96]

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Mark...put a rubber hose with a plug in the end and cap the opening, see if that changes idle quality.

Also I didn't look is your bike a CA model ???

 

[Oregonwinger]

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Sounds like a Calif bike. Calif bikes originally had a tube to the top center of fuel cap. Maybe someone put on a 49 state cap.

 

[Jack Joyce]

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It's a vent for the two carb float bowls. On the California model there's some sort of valve terminating it. For the rest of us it's just an open tube over the catchment tray. Don't inspect it with a match!

Jack