Taking off the stock "snorkel" allows more air intake but also will allow muddy water in (that gets splashed up there) which can cause your throttle to stick open. People do it to allow more air in which aids power output. But the snorkel is there for a reason. Too bad they didn't design it with a more voluminous intake. Once the muddy water cascades into the air box the air filter will pass it in because it only catches "dry" dirt particles with the air filter oil. The muddy water gets up there when it gets tossed "up" there while you are splashing through muddy water. My solution is to toss the restrictive snorkel and cut out a bigger rectangular hole. Then use something (I used cut out pieces from a quart sized mineral water bottle) that you can duct tape in place to build a 1/2" tall "wall" around the big hole to prevent creeping water from coming into the air box. Also you'll need to duct tape the front edge of the cover to the air box below. Also run a piece of duct tape from the left frame tube to the right one (taping to their undersides) in front of the air box which makes a splash guard there (behind where the frame makes a "Y"). Also tape the right upper side of the air box to the frame, effectively making a splash guard for that vulnerable side. These two mating surfaces let splashed water in. Also put a plastic splash guard under the area that's open between the tank and the frame. Also if you ride through deep streams you should silicone seal the air boot to air box juncture. If you have already drilled holes in the air box lid for greater air flow then this fix won't work for you and you'll need to buy another lid (they are cheap enough) and do it right. After all these fixes my air box still would ingest a little muddy water (but much less than before) from going through muddy puddles. So the final refinement was to put a piece of cardboard (sealed from water by putting packaging tape all around it) from the forward air box opening (secured in place with duct tape) to the near-bottom of the air box which basically provides a "chute" for the water to go down without getting onto the filter. Also I made the sides of the cardboard (about 3/8") bend up by 90 degrees (and held in place with tape) so that water won't get sucked over the sides of the cardboard and onto the filter. That way the muddy water just goes all the way down to the bottom of the air box. I finally put my noggin to work on this problem after I lost the last MX race due to the throttle sticking open with dirty water getting in. It was dissappointing because I was going to win and it was going to be my only win of the year. I got 2nd place the first moto and then pulled off the track with this problem while in 1st place in the second moto. I was all prepared except for this one weak spot - water intake prevention.