Air Box Flapper Removal

Our wonderful little WR250R/X's come with a flapper on the air box intake.  Why?  Hmmm . . . closest I can tell is that its main purpose in life is to reduce intake air noise.  I can see no other reason to have it on there.  It chokes up the intake something fierce . . . so let's get rid of it.

1)  Remove the seat, side panels, radiator shrouds, and the gas tank.  If you have a helper near by to hold the gas tank up out of the way, you will only need to lift it for a moment to get at a vacuum hose and you can leave both the wiring and fuel line connected to the tank if you wish.

2) Once everything is accessible, start by removing the electric solenoid by removing the Phillips screw as shown here.

3) Disconnect the electrical connection by pressing down on the tab and pulling the connector off and pry the vacuum line off of the flapper solenoid.  The vacuum line will want to squeeze itself around the nipple if you just try to yank it off, so it is easiest to help by pushing the back end with a flat bladed screwdriver as you gently tug it off.

4)  To remove the solenoid itself, turn it counterclockwise ¼ turn, then use a screwdriver to gently pry off the connecting rod going to the flapper itself.

5) Now is when you will need access under the gas tank to disconnect the vacuum line from the throttle body. This is easiest with a helper nearby to hold the tank up while you do the disconnecting.


6)  Install the small rubber cap (1/8") onto the exposed brass fitting.  If you purchased an AIS/Flapper removal kit from us, this cap is included.


7)  Remove black plastic surge tank which is held in place with a Phillips screw just like the electric solenoid was.


8)  Now that everything is disconnected, it is just a matter of removing all of the components from the bike.

9)  The last thing you have to do is fix the air intake flapper down.  Most people simply glue it down with JB weld or a similar adhesive.  Note:  the empty plug on the wiring harness left from the now removed solenoid can just be tucked in with the rest of the wiring beside the battery.

You can bolt the gas tank back down now since it is not in the way for the AIS removal.