Duck Beak Shaped Drain Valve/Tube?

Hi. My one way rubber drain tube/valve that is shaped like a ducks beak arrived today.
I was going to put it on the end of the crankcase breather hose which now vents to the atmosphere, and remove my one way check valve(as they are prone to failing sometimes)...but the slit in the end of it is quite big. there's quite a large gap.
I fail to see how water and dirt won't make it's way in with a gap that big?? especially if the bike stalls in water and it sucks water up through it...

As you can see from the photo, you can easily see right through it.
Either way, to me it seems like it can still suck water up through that gap...
Maybe someone else who knows more about these things can explain em to me? or let me know how water and dirt won't find it's way into it?


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They work pretty good on tractors. For things that may get submerged I am less enthusiastic. The principle being that under vacuum they are closed. When the pressure is from outside the box they are closed by that pressure as in being submerged. Once there is some dirt and sand involved, the theory that spawned the design seems to have some "leaks".
 
Floyd walked by. He was on his way to get a double shot of red-eye to wash down the BP meds, Lipitor and Geritol. Anyway he says you need to get a vent shaped like the duck's butt, not his bill. Swears the 'duck's butt' ones are made to be submerged.
 
I never tried that. Does it stop water from coming back up the vent tube?


Ummm, I really don't think anything will prevent water from entering a crankcase but then again I have had bone stock bikes sunk up to their seats in river crossings with no water in the oil or carb.
I have never tried this but just giving him options.
 
Water is funny. Sometimes I submerge one to the point I know it has to be FULL only to find traces MAYBE. Other times it seems like my bike is really prepped for it and the water only moderate to find I have been riding an aquarium with gears and a clutch.
 
If you go back and look at the way Doug Henry's yz400f was vented into his exhaust (there is lots more to his than a simple open line however) you can see how many of us learned to vent crankcases on v-8's back in the days of carbureted engines. the venting actually took on the form of harnessing the exhaust flow to create some vacuum and reduce pressures in the crankcase even more. this helped save seals and leaks, as well as reducing the pressure in the crankcase that the pistons had to overcome when starting their downward travel, thus reducing some power loss. I don't think any of my times at the strip showed it, but the mental boost was off the charts.

It is probably the ultimate in venting your crankcase if you can do it and not over do it, and suck out the oil.
 
Dw guys. I figured out my own methods and used my own way of venting that I felt most comfortable with.

Instead of using 1 one way check valve, I used 2 'T' pieces and used 2 one way valves instead.
1 of them acts as a secondary/backup in case 1 of them fails...because the chance of BOTH failing at the same time, on the same ride, is very highly unlikely. So it has 2 paths to vent out, if 1 of those paths/valves ends up failing...it can still vent out via the other path.
Then vented the breather hose to the atmosphere.

They're just something I'll do pre ride checks on. No biggie.

I wanted NO water and NO dust getting in there whatsoever, hence the reason for the dual check valve set up, plus I thought why not try it just to see but I actually like the set up.
And also, with 2 paths for it to vent out of, that'll make even less crankcase pressure buildup which is good.

It's barely noticeable on the bike and I took it for a ride to test it out and all is good :)
 
Dw guys. I figured out my own methods and used my own way of venting that I felt most comfortable with.

Instead of using 1 one way check valve, I used 2 'T' pieces and used 2 one way valves instead.
1 of them acts as a secondary/backup in case 1 of them fails...because the chance of BOTH failing at the same time, on the same ride, is very highly unlikely. So it has 2 paths to vent out, if 1 of those paths/valves ends up failing...it can still vent out via the other path.
Then vented the breather hose to the atmosphere.

They're just something I'll do pre ride checks on. No biggie.

I wanted NO water and NO dust getting in there whatsoever, hence the reason for the dual check valve set up, plus I thought why not try it just to see but I actually like the set up.
And also, with 2 paths for it to vent out of, that'll make even less crankcase pressure buildup which is good.

It's barely noticeable on the bike and I took it for a ride to test it out and all is good :)

There's more than one way to skin a cat......do a couple water rides and post an update.
 
Check out the venting on a CRF450R from 2005-2008. It's simple and it works and there is almost no way water will get in.

FYI: I converted my 2013 Husky TC449 to the same vent system as the Honda and it works grest.

Paw Paw
 
hey guys. took the bike for another ride. went through some pretty deep water crossings and I got no water in the engine whatsoever. So my method does work quite well.

I have another question though. As I am running to one way valves,
I routed a 'T' piece at exactly 3 inches up from my crankcase vent hose, then connected 1 of the valves onto that 'T' piece with another hose. The other valve comes off the side/middle part of that 'T' piece.

However, when I go to crank the bike, slowly, using the e-starter, I can hear a sound of air coming from the valve or from the line just below the valve that is connected to the 'T' piece and into the bottom of the valve.
Then after that it ends up hissing out of the end of the breather hose which is vented to the atmosphere.
What would that be?

I had thought it might've been that it's letting out all that compressed air inside the motor or something....but only 1 of the valves does it.
It also only happens at slow cranking speeds. When the bike is running, it's ok. The bike runs and idles fine.

I can also confirm that the valve is working correctly as I blew into the both sides, and I can feel air escaping out 1 side of it, but not the other, so the valve is definitely working. None of the vent lines are blocked or kinked either.

Image below shows the way I have it set up. It's coming from the hose just below the silver valve. Then when I move the hose a bit and pull on it, the sound of the air from that area stops...and still comes out the end of the breather hose like normal.
It's a weird one.

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without commenting on your hose situation that air is being compressed and trying to go somewhere. ie piston comes down and compresses air as it takes up space. I guess I can't really understand your question.
 
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