My '82 650 and the Mystery of the Hanging Airbox Line

[JimWilling]

Since searches have proved somewhat fruitless, no manuals show a picture of the airbox in it's full glory (or, frankly, mention them), and I can't see what it goes to, my question is this:

My airbox (between the carbs and the filter box, to be clear) has got a breather line out the top, which connects to the valve covers, and a little shorty line (maybe six inches long) on the bottom. Which connects to the atmosphere. Since this is post-air filter, I'm having a difficult time imagining why there would be a line that opens directly into dusty air right above the road surface. Does this attach to something? Should it? Was it cut? Was it a crankcase breather or something? Is it possibly the reason my bike doesn't seem to like starting or idling?

For reference, the bike has had its valves adjusted, the air filter is properly clean and oiled, the intake boot o-rings have been replaced, its carbs thoroughly cleaned (my roommate seriously does this for a living, i.e., beer money) and the o-rings done, the coils are within tolerance, receiving 12 volts (with a jumper; that's another project) and the exhaust is tighter than Charlie Sheen and blow.

I haven't pulled the factory emissions plugs out to access the air screws, but that's happening tonight.

Could this mysterious hose be the root of all evil? You decide!

[SqDancerLynn1]

Most of the air boxes have a drain tube on the bottom of the air box. Sounds like what you are referring to..

[JimWilling]

It's a drain tube? Sigh. I guess swearing isn't really appropriate.

[Steve]

..., its carbs thoroughly cleaned (my roommate seriously does this for a living, i.e., beer money) and the o-rings done, ... I haven't pulled the factory emissions plugs out to access the air screws, but that's happening tonight.

These two statements are at odds with each other.

If the carbs were THOROUGHLY cleaned and all the o-rings replaced, those plugs would already be out.

By the way, the hose is a drain hose. I have seen that on my 850s, but it was on the unfiltered side of the box.
I do not have a 650 with an airbox for comparison.

.

[spadefoot]

My 650 has a hole/spout on the bottom of the airbox as well. I always assumed it was a drain in case water got in there (condensation, perhaps?). It is on the "clean" side of the filter, as you say. I hadn't really considered the implications of that until just now...

[Vantreeseba]

My 450 has the same line, but its plugged, there should be a weird little cap on the end of it, at least in mine, its so that the gas returned from the breather line at the top drains into it and the vapors are reused in the engine iirc.

[Big T]

I'm with Steve

Go whack your room mate in the head and make him read the carb cleaning tutorial

He's not completely cleaning the carbs if the mixture screw is undisturbed

I'm guessing the emulsion tube isn't clean either, which is why it doesn't want to idle

All the GSes have some sort of airbox drain line. That's not the source of your troubles

[Nessism]

Yet another case of "the carbs were cleaned". Wish I had a nickel for every time someone says that.

[refeicul]

Yet another case of "the carbs were cleaned". Wish I had a nickel for every time someone says that.

hey hey sometimes the carbs were cleaned then they threw it all back together and forgot about it for 6 months to a year....