99 400EX bought w/ HMF slip on, K&N, jetted (don't know what jets). Now I'm 38 and this is my first quad (rode lots of dirt bikes as a kid). I rode trails Saturday down by a river in Indiana and was with 2 others (they had 4x4's). I went through a few good water holes (not submerged) and did great. After a four hour ride when it was time to head back I started bogging down when under heavy throttle and under a load. Well today I found the air cleaner covered in leaves, a little damp and about a half inch of water in the air box. The air box lid is clear with four clips at the top and has three holes in it ( AFTERMARKET ??????? ). The oil looks great, not mulsified. I am planning on cleaning the carb (wanna know jet sizes anyway ) and am thinking about changing to a UNI air filter. The water in the airbox kind of surprised me as the water holes weren't a concern for me @ the time. I am going to change the oil/filter again anyway as I hate the sight of water. I just wonder how often people here get water in the airbox and how big of concern it is. I'm not planning on scuba diving w/ it but I can see some of the same type of riding in the future. I guess what I', saying is, "What would you guys do for a filter / air box lid ?"

One more thing, I do keep my K&N clean and oiled frequently, was thinking of adding an Outerwears foam liner but I'm undecided on whether I like the K&N or not. Thanks for your help/replies.

 

I would say if your really conserned about it to get an outerwears air box covers and just put it under your stock lid. They are water repelent and will still let lots of air flow past. Also 400EX's weren't exactly made to be waterbogging with.

 

I'm not sure if I have the stock lid. Is it black and solid? I have a clear lid w/ 3 holes (made that way, not drilled into). I will probably get an outerwears skin for my K&N and avoid water as much as I can. Thx again.

 

The stock lid is black with no holes.

 

That's what I thought. There was just more water in there than what I thought I would find. The filter did do a good job though. My intake looked clean and dry. Oil & filter change showed no signs of anything foreign, hopefully carb will look good also.

 

Do you still have the snorkel on it?

 

Yup, the snorkel's on it. I just got done cleaning it and the air box. However, there is a small nipple in the bottom of the box. Is this supposed to just be a drain? This seems to me to be where I'm sucking in unwanted material from. There is nothing there. I'm thinking I should block that off. The Clymers manual I have doesn't show it but should it be open like that? THX again

 

there should be a rubber nipple looking thing the on the bottom of the airbox.......and you pull it off to drian if its not there i would get one

 

Not a bad thing to have. You can tell if there's water in it just by looking at the bottom of the box. I would replace it instead of blocking it off.

 

Thanks a bunch. I'll check again but I don't think the Clymers showed that. I'll call Honda tomorrow to see if they can get that for me. It's kind of a relief finding out where crap was coming from because I rode some rough trails with some water but it should've been far from entering the snorkel or air box lid. Just glad everything else looks good so far. Good thing I recharged my K&N right before I went out. LOL