Did the old filter a favor today and treated it to a shower in Kero' and a wash. Then hung her up to dry overnight ready for a good dose of Motul in the morning.
While I was at it I decided that the gauze screen behind the filter is unnecessary. (Read that small bore thumpers rarely suffer from backfires through the carb', and I'm sure it's restricting the air flow quite a bit.) A few cuts from my trusty Stanley and it was consigned to the bin.
Work beckoned, so it'll get finished in the morning. Just some emery cloth to smooth the edge of the gauze and the plastic edge. I took some photos if anyone is interested? I'll post them when the job's finished.

 

I cut mine out too. Even if you get a backfire, I think that the chances of the filter catching on fire is slim.

 

Why is it there really?

 

This was a hot topic quite a while back on here. The screen will disfuse any flame from a backfire that would try and make its way to the filter and airbox. By removing it there is a risk of the filter catching on fire. On the up side it is reported to flow a lot more air and produce a pony or two more with proper jetting.

Some companys actually make a backfire filter that is supposed to be flame resistant. There isn't one that is a direct fit for the klx250/klx300. Someone found out that the filter from a different bike would also fit the klx250(I think that it was the yz250f, but I can't really remember) They make a backfire filter for that machine and that was what some were running on here.

The part number for the filter was on here at one time. I was running the filter with what part number that on here for a while, but honestly I went to one that was bike specfic for the klx300 and it seems no different than the backfire one and it also fits much better. They were both twin air filters.

 

I'm running a KLX300 Twin Air. Let's see if I can feel a difference when I put her back together. 2 more ponies sounds good for an hours work.

 

Is there a chance that without the screen the filter or part of it could get sucked into the carb? Just thinking out loud.

 

ROFLMAO.
No way dude.
What are you smoking?

 

Just trying to help. I mentioned it because I had an old 85 KLR250. It had a different filter arrangement than the KLX. It was a flat filter squeezed in between a metal frame with a metal screen on the carb side. One time when I was cleaning this filter I noticed that the filter foam was actually starting to crumble. Obviously that filter had been reused more than it should have been, I was glad at that point that the screen was there though. I'm sure you take better care of your bike than I did that one, so no worries. I was just tossing it out there, thinking that is may be more than just a backfire screen. Rock on

 

The chances of flame shooting backfires increase if you are using a pumper carb, but I've never seen this bike catch fire due to that.

 

K&N filter has a metal frame. No backfire screen here.