Airbox Before Mod

Airbox After Mod

Directions: With the airbox in the subframe, I took a pencil and ran it along the inside edge of the subframe to roughly mark the new opening. I then removed the airbox from the subframe and used a straight edge to make a nice line to cut. With the straight lines drawn in, I used a drill to drill out the corner so they would be rounded when I cut out the top (any size bit should work, just depends on how round you want the corners). With a Dremel tool and a cutting disc I went to town cutting on the line I had drawn in. Once cut out, I used a file to smooth up the edges. Finally I cleaned out the plastic from inside the airbox and put everything back together.

Jetting: With this mod, I did not make any jetting adjustments, due to my bike was running slightly on the rich side at the time of this mod.

Improvements: What I noticed right off the bat was a much crisper throttle response, the engine seemed to rev faster than before. All in all there was a noticeable "seat of the pants" improvement, best of all it made my jetting perfect.

Mod Drawbacks: If you ride in a wetter climate or cross rivers, opening up your airbox like this will make it easier for water to enter you engine.

The main reason why I tried this mod was that all the 2 strokes I have seen have an open airbox like this and seemed to do well where I ride. If you have done all the free mods and are looking for a little more, this would be one I would recommend. With proper jetting you will notice more power and a big grin hiding behind your helmet.

Credits: Submitted by ThumperTDC to our "Best Low-Buck Mod" Contest, and edited by 4Strokes.com.

Addition to Mod: If you have modified your airbox and have a gauze type air filter, you may have noticed how much junk gets caught in the air filter. I get pieces of dirt, small rocks and some weeds in my air filter. So I made a pre-filter by using some open cell foam, the type used for small air conditioner filters. It can be purchased from most any hardware store. I cut two pieces to fit over the opening of my modded airbox. Then I drilled some holes in the top of the airbox to secure the foam with plastic push-in type fasteners (used for car door panels and such). I just push the plastic fasteners through the foam and into the drilled holes.

Credits: Submitted by Royo to our "Best Low-Buck Mod" Contest, and edited by 4Strokes.com.