removing the backfire screen on your air filter cage

I removed the cage on a 2014 350sxf that I had. Couldn't tell the difference.

It’s not a Night & Day difference, if even an advantage. To be honest, when I wash my bikes, I put a double layer of paper towels over my air cleaner, to keep it from getting wet while washing. On more than one occasion, I have forgotten to remove it after washing the bike. I noticed ZERO difference in HP or any loss of power.

I think it’s a little piece of the puzzle to make the bike run better. Filter cage, fuel + mapping changes are noticeable.

Didn’t they implement the screen because some early 4 strokes caught fire?

I remember Honda sent out screens for my 02 CRF450.

If it was that easy to make more power, the OEM's would have started removing them long ago. You would have to heavily modify the throttle body, port the head, more aggressive cams, etc before the backfire screen was the restriction.

Spend the money on tires and suspension. 0.05 extra hp isn't going to give you faster lap times. Good tires and suspension dialed in personally for you will lower lap times.

Can't remember where I saw it maybe on an mx mag a few yrs. back they did some dyno runs with & without the screen on a 450. There really wasn't much of a change if any at all in HP/TQ from what I recall.

It won't change horsepower, it will change throttle response making the bike snappier.

I do it only because makes it easier to clean it, I could never really tell a difference, but also that’s one of those things you would have to do back to back same day to realize if it made difference.

Removed mine on my 19CRF450 and put it back in not long after. Not a big change but I think it made the throttle response snappier which is not what I need. I don't understand the comments about being easier to clean without the screen. I rarely get any dirt on the cage and like the piece of mind of having an additional screen behind the filter.

I don't know if it makes any difference as I've only ever owned one 4t (2008 YZ 450) and it had no backfire screen when I bought it (bought used).

What I do know is that the Twin Air Powerflo kit for the modern YZ's has you remove the backfire screen. I don't know why exactly, but I just followed the instructions when I helped my buddy install the kit on his 2019 YZ.

What are these "backfire screens" of which you speak? And what's a backfire???




Braap.

Yes. Get one. IMO

I know it makes enough of a difference that the LL's championship requires that they be in the stock classes and if removed you will be disqualified.

Paw Paw