Carb vent hose discovered missing... Keep it off?

[vcalvarese]

Hey ya'll,
So in my recent adventure with installing a set of green Dyna Coils on my 82 GS1100E, I stumbled across this hose routing thread - http://members.dslextreme.com/users/...locations.html.


After some inspection of my bike's setup, i've found that the carb vent hoses are not there (and appear to not have been there for some time).

I've searched around a bit and found this thread -

http://www.thegsresources.com/_forum/showthread.php?81552-Removing-carb-vent-lines-solves-starvation-mystery

What is the general consensus here for stock bikes? Keep the thing, or just leave the hose off?. The previous owner did tell me that when he bought the bike there was an aftermarket exhaust on it, but he replaced it back to stock. Potentially there were carb jet modifications (or pods) that happened as well, but were never returned to stock. I just don't know, and don't know how to determine this. Currently the bike has stock exhaust and stock airbox (and runs like a bat out of hell). I would be inclined to put the vent hoses on if I didn't read that post suggesting against it, but i'm concerned about crap getting into the carbs.

thoughts?

[Steve]

Unless you start riding through dust storms or crossing deep rivers, there is likely no crap going to get into your carbs through the vents.

I don't know why some people think that there is any air flow through the vents. The only time that air might be considered to "flow" would be if the bowls are empty and you fill them with gas. The little bit of air that is displaced by the gas will have to flow through the vents. At any other time while the bike is running, the fuel level is virtually the same all the time, so there is no "flow" through the vent. The reason it's there is to provide an atmospheric reference to a enable the carb jetting to do its job. Whether the hoses are there or not, the vents need to terminate it relatively still air. In the stock configuration, the hoses usually run to a point behind the airbox, usually up under the seat. When the airbox is removed to install pods, that area now has more-turbulent air, so the suggestion is made to remove the hoses, because the end of the vent nipple is now about the least-turbulent air available. If you install longer hoses (with pods) and run them to calmer air, you will accomplish the same thing, but everybody chooses to pull hoses instead of spending money for longer ones.

In your case, if the bike runs fine without the hoses, don't worrry about it. If you are concerned about crap getting into the carbs, just make sure the vents are pointing DOWN.

.

[vcalvarese]

Great info Steve,
Thank you!