Those pesky vent tubes

Well, my resurrection project is alive, and I've logged about 500 miles thus far, and the only question i can come up with is this:

My bike seems fortunate enough to have both vent tubes, and I have seen talk about adding and/or removing one, but what I cannot find anywhere is something that shows me just where in blazes those things run to.

They look like they clip into something, but I'll be dogged if I can figure out what.

MK

Which vent tubes? Under front cowl to aft air vent? Battery vent? Fuel system vent?

Sorry, the ones that run from the front cowl back to who knows where because all the tupperware was off when i got the bike

They just run along beside the airbox, so bring them up from their front attachment point, along the airbox side and then there is a little "hook" on the airbox, towards the rear, where the hose attaches.

Also, IIRC, there is a U shaped holder that the hose sits in on its way to the rear.

As you put the plastic back on, you may find you need to alter the hose position slightly for all to fit, as it is a bit snug in there.

Ok, cool! That is pretty much where they landed anyway, so next time I'm under the plastic, I'll try to route them cleaner.

Thanks!!!

MK

Kramer said:

Ok, cool! That is pretty much where they landed anyway, so next time I'm under the plastic, I'll try to route them cleaner.

Thanks!!!

MK

Click to expand...

Be careful to not crimp them when you put the plastic back on. When I bought my 1991, I found the right side duct was squashed into a 'U' cross section through most of the tube's length. Little air was passing.

Does having both make any noticeable difference in how the bike runs?

Woonjas said:

Does having both make any noticeable difference in how the bike runs?

Click to expand...

It didn't make a difference on my 1991. I discovered the right tube was crimped shut along the whole length of the tube into a 'U' cross section...it looked fine from the outside. I replaced it with a new one. Didn't notice any before/after difference in the way the bike runs.

Figured as much, I mean after all, it's not like those hoses are hooked up to the airbox directly, forcing the air in.

They are cooling air vents, probably end up where Honda recognized a problem with heat build up.

Some 1100 owners, particularly those that live over the pond in a more damp environment, have claimed the vent tube(s) bring in more moisture directly to the airbox intake area, creating carb icing under certain conditions. Maybe?? Maybe not??

Woonjas said:

Does having both make any noticeable difference in how the bike runs?

Click to expand...

Installing the 2nd duct (omitted post '91 production) cured vapour-lock issues at take off's after idling at red lights during hot summer days on all my STs...
Cooler, thus more dense intake air should improve filling ratio...

Rumour tells the 2nd tube has been omitted to solve occasional carb icing symptoms faced by folks in coastal areas in cold winter climate...
Never experienced such, even during days with temps well below freezing... but its embarrassing (plus dangerous) if the engine nearly stalls after like 15~20 feet when the light changes to green in dense urban traffic...