Gas tank vacuum hose. Grrrrrr.

I posted a few days ago about taking off my gas tank to route wiring for my Stebel air horn, and after replacing the tank the engine starts but quits after the float bowl empties. It was suggested that the gas tank vacuum hose may have been kinked or off at one end (Thanks guys).

I found that the tank end was loose and replaced the hose clamp with a stainless screw on type. It fired right up. Problem solved... until this morning when I fired her up to go to school. The idle was really fast (even for the choke being on) and by the time I got my helmet on my noggin she'd stopped running.

On the way back from school in my 4 wheeled coffin I stopped and got a gallon of gas; perhaps my baby had run out. Not so. It will only start with the choke on and the gas valve at PRI. Moving to "reserve" or "on" immediately stalls the engine. Did I mention that she idles fast... real fast, maybe double the speed when normally choked.

I think it fairly obvious that there is no vacuum to the tank but the line does not appear to be kinked or otherwise screwed up... as far as I can see. Which brings me to a couple of queries. Where does the other end of the hose go to. It disappears towards the rear tire and short of really taking stuff apart I have no way of knowing where the end of it is. Does it go to the carb? What part of the carb exactly? The canister? The Twilight Zone? :thumbsup: My downloaded repo copy of Clymers is vague and the pics are not very clear.

The hose in question is extraordinarily long; at least 8" too long as far as I can reckon. It curls and twists around below the carb and the rear of the block before heading up to the petcock. Is it possible that I have managed to find some other tube and connected it in error thinking that it was the vacuum tube? This tube that I've connected is covered in some kinda black plastic outer housing (a real loose fit)

Stock carb, 3X3, (I assume the previous owner did the jets as well, but honestly dunno) really loud Yoshi connected to the stock (unfortunately) header.

I need an anti-psychotic. Not being able to figure this out is driving me crazy. :confused:

I think you may have connected the wrong tube. It should go from the petcock to the closest vaccum sorce, such as off the intake. Mine is a FCR and it connects to the vacuum source off the head that is created when installing a FCR. Sounds like you may have connected to some type of overlow hose?

Took some Abilify, Klonopin, and had a coupla glasses of Australian Shiraz. Feeling much better.

Pulled the tank and the 2 hoses off and LO & BEHOLD, here's this little tube coming up over the carb from the right hand side (thanks NPM) and it must be the lost vacuum hose. HALLELUJAH!

So where does this other hose that I've trying to get to work AS the vacuum hose belong???? Fortunately an elderly neighbor is walking by and sees me with my now calm exterior and as sidewalk mechanics go he turns out to be pretty good. After explaining the intricacies (such as I know-not much; and as I am able-not very ably considering the wine etc) of vacuum operated petcocks he points to a tiny little vent on the rear underside of the freakin' tank and asks, "Waz dat?"

The long hose was the breather/crankcase return/whatever to the tank, and I had been trying to utilize it as a vacuum hose. :confused: It must have fallen down when I pulled the tank off and landed right by where I would have expected the vacuum line to be. Damned if I knew there was a breather tube. :worthy:

Anyhow, now that it's all apart I'll take some pics of the brackets I fabbed for the horn and post them.

Thanks be to snailspool and NPM for prompt replies to my desperate situation. :thumbsup: I'm indebted. Come by and have some :busted: Shiraz.

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