Bottom of the air-box hose?

[sre15]

I just got done cleaning and rebuilding my carbs on my 81 GS750E. First time doing this and learning lots. Getting everything put back together over the next couple of days and I see a hose connected to the bottom of the airbox. Does this plug into anything? Or is it left open? If left open for air draw where does this get fed....under the battery?

Also any pro-tips on getting these carbs back into he carb boots? I'm having a bugger of a time getting them to seat in all the way.

Thanks everyone, great group here.

[Rich82GS750TZ]

Warm the boots with a heat gun and a little WD40 can get the carbs into the boots provided they’re still supple and not hard and cracked.

The port at the bottom of the forward airbox is a drain. It gets a hose that runs to a sqaureish opening at the right rear of the engine base so it drains to ground off to the side instead of directly in front of the rear tire. The last one I bought came with a plug and hose clamp. I just empty the few drops of oil vapor that collect out of there every few hundred miles or so. The fuel tank sending unit gasket drain (there only for/if that gasket ever leaks), and the battery overflow drain (if you still run a fillable lead/acid battery with a drain) should be run to the same location.


see here. Part # 9

https://www.partshark.com/oemparts/a/suz/50d40081f8700230d8b4e2ca/air-cleaner

[sre15]

Thanks for this tips and this photo. They are very helpful!

[tom203]

The factory hose coupling/fitting at bottom of airbox is to drain liquid overflow when there’s no suction in airbox …I.e. engine not running . When running, it likely contains a small plastic ball that sucks upwards and blocks this opening. Similar principle to that ping pong ball in a wet/dry vacuum that shuts off when it’s full.

[Burque73]

The factory hose coupling/fitting at bottom of airbox is to drain liquid overflow when there’s no suction in airbox …I.e. engine not running . When running, it likely contains a small plastic ball that sucks upwards and blocks this opening. Similar principle to that ping pong ball in a wet/dry vacuum that shuts off when it’s full.

Sort of like a check valve....
Mine is just pinched on the end so the hose closes while running.