Why not just re route the vent lines so they are higher off the ground and zip tie them so they are still pointing down? Cheaper and easier than adding Y's.

 

I personally wouldnt want gas shooting out of a tube on a high point on the bike, what if the gas comes out on the right side and hits the exhaust and catches on fire... even if it isnt directly above the exhaust there is a chance that could happen. I cant think of a "good" place to put the left one either.. I think its just best if it dumps out under the bike. Then your taking lines off the carb that should go down and pointing them up. I would not want to make the lines higher than the carb so it drains properly. IMO its just best in every aspect to Y it. My bike gets sleepy alot and lays down so its a common thing for me, maybe not you.

 

Y vent, so the gas can exit near the ground. Like Eric said, having gas come out up high means there's always the risk it'll hit something hot on the way down. Bad!

 

Another consideration: IF (or when) gas does come out of that vent, unless it has a way to exit downward, it will pool in the line. A section of line with gas in it can act exactly like the vent is plugged, causing the engine to stop. So, the correct way to do this is to run the tube downward from the carb...somewhere in that down-tube, a "T" or "Y" can be spliced into a line that goes upward. Many people run this upward running line under the seat or (better) out the rear of the left-hand side of the bike. Do it right, or don't bother doing it...you can cause yourself some unintended trouble.

 

Its not very expensive for a few fittings and some tubing.....

 

Yes the Y mod was one of the things I did before heading on a trip over by Monroe Washington nearly 4 years ago. It probably saved me as we were riding through 2 ft of water.

 

So my stock 2009 has been through enough water to cover the engine and I haven't seen the problem yet. It ran great like a frog. My last few XRs also had vent lines that ran only to the ground. What is the problem that we are trying to solve?

 

Unless they changed it, when you would run in water that would be deeper than the carb vent lines the bike would stall out. The fix was to T the line and run additional lines up so when you go through deep water it still vents. but you need the lines to go down still when you lay it down and the gas dumps out. You can test if your bike will die in water or not, get a big cup of water start the bike and put the two vent lines from the carb, by the bottom of the shock, in the cup of water and wait a few seconds to see if it dies. It should... this just isnt the KLX almost all bikes are like this i believe

 

I feel like I recall reading a thread where guys discussed that they did plenty of deep water crossings and the vent lines wouldn't cause a stall but that the boot on the plug wire wasn't the best fit and any water high enough to get in that area would cause a stall instantly, almost like an off switch. A good gasket sealer fixed the problem for a guy who tested this theory in his driveway and found that every time he got water by the spark plug area with his hose it stalled immediately. He sealed it up and no more stall problem.

FWIW I haven't tested it either way on this bike, but usually a vacuum lock wont kill a bike straight off, it takes time to create enough negative pressure to stop gas flow completely (and then you have to empty the bowl enough to cause a stall after the flow stops)

When you drive into water, there's natural air pressure in the tank, even with a potentially perfect seal, at least some gas will still come out before it vacuum locks and wont drain any more. You could drive on that gas plus whatever was in the carb bowl when the water first sealed the vents before you stalled out. The more empty the tank was when this happened, the more initial air volume and the more gas that could keep filling the carb before it locked up. This bike can go a long ways on a little gas, so unless the tank was REALLY topped off, I would be surprised to see a vacuum caused stall short of riding through a very long flood zone or a really wide river. Even if no gas came out of the tank carb, I wouldn't be surprised to see that this bike would make most average deep water crossings just on what was in the float bowl. My .02 cents... if I stall in water crossings, I'll probably check the spark plug issue first, then try the vent tubes.

If you really wanna test it for sure. get your tank half empty (median test) plug your vent tubes on purpose with some caps, pull your gas line off your carb, flip open the petcock and see how much gas comes out. That'll tell you how much extra you would have besides the float bowl to run on in a water crossing.

 

Its not the gas tank lines, its the carb vent lines man. The clearish lines off each side of the carb, the same ones that dump gas when you lay it over. My bike would stall with in 5-10 seconds of running in water deeper than the carb vents... now that i have it T'ed i dont stall in water at all... The slide i believe needs an atmosphere vent so it can move back and fourth... Im not 100% sure why it needs the vent, i just know it needs it.