Stole this idea from my motorcycle.
After fording some muddy water I found water in the bottom of my airbox so I bought a couple of dirt bike drains off Ebay for around $5 each. I grabbed a copper plumbing fitting (1/2" sweat to 1/2" thread) and two romex connectors.



Using a thin piece of plastic I drilled it to fit the two drains. It's hard to see the thin plastic but this is assembled. Hole saw is 1".



i then sprayed the whole thing with liquid bed liner (optional).

Then drilled two 1 1/4" holes in the bottom of my intake. I have an Airaid intake but I'm sure this will work with any intake box.



To seal the drains I used RTV sealant all around the drains.



Placed it in the bottom then sealed around the edges.



That's it, for around $15 this will let water out but not in (unless it is sitting submerged for a while).

 

I saw one other person do this when they made a homemade snorkel vs just totally sealing it off. He called the part a duckbill drain.

QUESTIONS

1. Can you copy and paste the model number, and/or the name used in the listing. An actual ebay link would be cool to, but those can expire.
2. So this will bascially just do a slow drip right. Have you tested it?
3. The clear plastic seems to be not all that necessary. Were you thinking you could cut a more round hole for a tighter fit. Seems like you could have just cut a 1" hole in the air intake vs 1-1/4".

Thanks for posting

 

Here is a "valve or drain" from a 2005 Honda CRF100 $3.32, Keep looking on Ebay, they pop up for a good price or a local cycle recycler. The ones I bought were from an 88 KAWASAKI KAF450 B1 MULE

17358-170-000 - TUBE, DRAIN - Honda OEM Parts - Cheap Cycle Parts

It's a little more than a drip, it will give a steady thin stream depending on how much water. The more water the faster it will run out.

The clear plastic I used was only because I didn't want to remove the airbox. If you take the airbox out you can drill the 1" hole and sandwich it together just make sure you seal around the inside and outside.

Depending on the airbox drain you get, you can also use a close nipple (plastic is best) from the electrical or plumbing dept. at Home Depot instead of the copper. You get the idea.

Search Results for*close nipple*at The Home Depot