If the backfire is strong enough, it could possible make its way out of the snorkel or even bow the air box cover. But, then again, if its that bad, something was wrong to begin with.

All this talk about getting more power. Glad some of us are willing to take some experiments with their KLX's. As for me, stock does me fine. But this thread reminded me that I do need to clean my air filter.

 

Hey Minarko! Is that avatar one of your own creations or an Estes kit. Got a few rockets myself. Nothing too large as we have pretty heavy restrictions down here on black powder etc. Saw a doco' the other day where they made a 'pulse jet' for a drag car. Awesome. Loud beyond belief.
http://www.youtube.com/watch?v=-O80JRk03jU

 

After dumping my '07 over on the exhaust side in a creek and then not tipping the bike up on end to drain the water out of the muffler caused mine to backfire a couple of times before all the water was blown out the exhaust. Thankfully I had the KDX snorkel on and water didn't get in the airbox and the engine didn't hydrolock. When I got home and looked in the airbox, my new TwinAir filter was toast and the plastic cage was melted and deformed. Thankfully, again, the filter was still sealed to the airbox enough to do its job. So, in search of the elusive .10 hp is it worth it to take out the backfire screen? Not for me. BTW -Is there a backfire screen in the airbox for the KLX300R?

 

ditto

 

There isn't one in a WR250F, RMZ250, CRF250X, TE250. All performance small bore 4 strokes. I don't have the airbox lid. There'll be plenty of water in there to put a fire out before it starts.

 

Yes, the KLX300's also have the back fire screens and mine has been gone a very long time. I also run an FCR35 pumper carb with no problems.

 

Same with the direct mount K&N equivalent I'm using..screen's built-in, although the weave is pretty loose/wide