My airbox lid mod: Protection and performance (Hopefully)

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TheRadBaron
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My airbox lid mod: Protection and performance (Hopefully)

Post by TheRadBaron »

This subject was once again beaten nearly to death recently so I don't want to get back into that. That thread did get me thinking, though. I know that lots of people run without the air box lid and have no troubles but I'd personally feel a lot better if I had something there to keep muddy water out. It's the gritty particles of dirt suspended in muddy water that could potentially get through the air filter that worry me. I'd like to make my top end last as long as possible and I'd just feel a lot better about attacking a large mud hole if I knew that my filter wasn't going to get splashed. Last time I went out riding I got into some moderately muddy conditions and my filter looked like this afterwards;
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Not too bad but there's enough mud splashed around that I feel like something should be done. Also, the mud could have been a lot worse that day.
I went into this a bit in the last thread where this was being debated but I'll lay it out here, too. The original inlet hole in the lid is pretty small so I figured that I'd enlarge it and build a baffle to direct any mud or water away from the filter. Here's the hole before and after; The new hole is about 4 times as large as the original.
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I used some aluminum roof flashing and a rivet gun to fabricate the baffle. I made it with a raised lip that sticks up about 12mm from the top surface of the lid so that any liquid that gets onto the lid can't run down the hole. Then I riveted a chute onto it and bent the sides up. This should direct any liquid that gets into the hole away from the filter and into the bottom of the air box to drain out. I used some epoxy to position the aluminum piece into the lid then sealed around the perimeter with RTV. I would have rather used black but that tube turned out to be all dried up so blue it was.
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And here it is installed onto the bike. Hopefully this will keep the majority of the mud off the filter without having a real impact on performance. I know that it will make me feel better about the universe. The picture makes it look like the aluminum flap nearly closes off the airbox but there's really a lot more open space than can be seen in the picture.
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royadams
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Re: My airbox lid mod: Protection and performance (Hopefully

Post by royadams »

Looks like you closed up the air opening with the piece of aluminum. Opening bigger at the top then making the opening smaller at the bottom will still restrict the flow.
TheRadBaron
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Re: My airbox lid mod: Protection and performance (Hopefully

Post by TheRadBaron »

I would agree if that were the case. The last picture is misleading, though. There's quite a bit of open space in the airbox for flow around the baffle. Still, I'm thinking that I'll probably shorten the aluminum flap up a bit. Most of the mud seemed to be coming in from the front of the air box so the flap probably isn't doing a whole lot, anyway.
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Jaguar
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Re: My airbox lid mod: Protection and performance (Hopefully

Post by Jaguar »

A job well done. congratulations!
nothing like having confidence you can go thru mud without having to worry about ingesting muddy water.
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/
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bufftester
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Re: My airbox lid mod: Protection and performance (Hopefully

Post by bufftester »

I agree that it appears most of the mud is coming from the front of the airbox. You have a gap between the front edge of the airbox and the frame just above the shock. On the KXs there is a plastic shroud that covers this area and may also help eliminate some of that water migrating to the top of the airbox. (you can see it in the pic below just behind the tank
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