[Alan Naylor]

So, in the process of removing the fuel tank from my little project bike here, I've found a problem. I've got two vac hoses that aren't connected to anything, and I can't find where they go!

How many vac hoses are on this thing? I'm searching the Clymer guide and staring at the engine from every angle with my drop light, trying to find the places they go to.

Help!

 

[93gc40]

On mine there are 10 hoses. Some are VAC some are VENT. Pics would help.

 

[xsive]

Pictures would help but one you may be seeing goes to the underside of the tank. A hose coming from the T on top of the carbs just runs down to the lower left of the engine and connects to nothing at all. Here is a link to possibly help. Also look at the inside of the battery side cover. It should show a vacuum hose diagram.

Carl's Cycle Sales - Honda, Suzuki, Polaris, Kawasaki, Victory, KTM Powersports Experts, Boise, Idaho

 

[Alan Naylor]

Alrighty, I found the end of one hose. It goes to the plastic manifold that feeds the carb intakes. THe other end of that hose came out on the left hand side of the motorcycle down below and just forward of the battery and rectifier.

The other hose was just sitting loose, about 15 inches long.

 

[Alan Naylor]

So the first hose that goes down to nowhere, checks. So that really wasn't much of a problem. That leaves me with this second hose that was just sitting there under the tank. Sadly there is no drawing of the vac hose system anywhere by the battery compartment.

 

[jchargu3]

Your hose on the carb is an atmospheric pressure vent tube, never plug it, don't remove it.

Alan, could you take a picture of the hose you're talking about and post it? It'll us diagnose whats missing for you

 

[93gc40]

Did you re attach the vent hose on the bottom of the fuel tank, could be your mystery hose?

 

[landon]

@ Alan Naylor, does your motorcycle have the charcoal canister hanging under the radiator?

 

[Rock]

This old discussion seems to have died without being fully diagnosed, and I have the same problem with figuring out vacuum lines on a VT700 (1984). This bike was a disaster which was disassembled by at least two prior owners with many missing parts.

Note: This is a California emissions bike, so there is a charcoal canister under the radiator and there may be some additional lines that are not present on normal bikes in normal states.

In the photo I have circled and labeled hoses A, B and C which I need assistance with.

I think C goes to the gas tank vent at the left side of the tank.
A and B are the same hose, and C fits the T vent that runs in the center between the carbs, but not sure......

 

[Jammit]

section 1-14 of the service manual shows the entire map of the California Emmisions System. You live there, so maybe you have to connect it all back in order to get plated legally? I'd rip it all off if it were mine, but the smog police here in Illinois aren't quite as picky on vehicles over a certain age....YMMV.