Mountain max/ SX Air Box Modification

#1- Remove top half of air box and snap-on snow filter

#2- Drill six or seven 1" holes in the recessed area, right in front of the
stock air inlet on air box. Try to keep them in a nice row, evenly spaced.
Remember, if the little snap on snow-filter doesn't cover the holes, you are
drilling where you shouldn't be.

#3- remove the baffle plate that is sandwiched between the top and bottom
halves of the air box. Drill the same holes in the baffle plate as you did in
the top of the air box. Drill them right in front of the air ports in the
baffle plate.

#4- Chamfer the holes you drilled, removing any loose plastic or debris.

#5- Re-assemble the air box, with the baffle plate installed.

#6- go up one jet size across the board if you are jetted properly.

#7- typically we have seen two to three horsepower gain on the dyno, and
probably more in the mountains at higher altitudes.

#8- you could possibly have to put a fatter pilot jet in if it starts to
lean-bog off idle when the throttle is snapped open. This is due to the
increase in airflow.

From Bob @ Mad Max Yamaha Performance

Totallyamaha is not responsible for any damages that these modifications may cause to your vehicle; any modifications are your responsibility if you choose to do so. We are providing information ONLY. Some of these modifications may VOID your warranty and that is your responsibility to look into. The Totallyamaha users have passed along most of the information found on this site. If you have any questions or concerns about anything on this site talk to your dealer before using any of the information. Totallyamaha will not be liable for any damages or personal injury from any modification performed from this site.