Backfire screen - keep or remove?
Posted November 26, 2007 - 11:30 AM
Posted November 26, 2007 - 12:59 PM
I have an 05-WR450 and a 06 WR250 that I am working on the mods for. I am trying to determine exactly what airbox mods to to. As a minimum I will pull out the snorkel (opening up the extra space in between tubes). But that backfire screen seems awfully restrictive. It can't be more than 70% open. It seems like all the other mods are a mute point unless that screen is removed. Anybody have any performance data on the air filters with the fire retardant material? I have read that some feel the new air filter is actually more restrictive than the fire screen. Thoughts?
Tests have shown that the filter (even a good after market filter) restricts airflow more than the backfire screen. Therefore, you would be gaining nothing by cutting out the screen.
Posted November 26, 2007 - 01:03 PM
Posted November 26, 2007 - 07:12 PM
Posted November 27, 2007 - 06:22 PM
By the way, I was also able to improve air flow by matching the carb to engine rubber flange inner bore, which closes in when tightened, as well as remove flaws and ridges at the airbox flange, etc.