Having trouble fitting the air filter to your Yamaha YZ250F or YZ450F? Here's a few tips from our Tech Editor Mat Boyd.
The YZ’s have had the reverse style engine for over a decade now with the air filter fitted at the front of the bike where the fuel tank used to be. Over the years they have changed the design slightly with different shaped air box lids and different shaped air filter. The 2024 YZ250F and the 2023 and 2024 YZ450F have the new tool-less design where the air filter is held in place by a rubber strap at the front of the air filter. While this seems like a very easy and foolproof filter to fit I have already seen people fitting them wrong which has inspired me to put this how to together so that nobody goes and dusts out the engine on their new bike.
#1 OFF WITH THE SEAT
Start by removing the seat. To do this you remove the dzus clip at the front of the seat by turning the clip half a turn to the left. Once you do this the clip will become loose and you can lift the section of seat out and hang it out of the way. Then remove the fuel tank vent hose and let it hang out of the way.
#2THE BIG REVEAL
Now grab the air box cover with your fingers at the back corners and lift it upwards. You will feel a click and the cover will pop loose. You lift the cover all the way up and then remove the cover from the motorcycle.
#3 UNSNAP THE STRAP
No it’s time to remove the air filter. Grab the rubber strap at the top of the air filter and lift it up and away from the air filter until it pops loose. Then you will lift the front of the air filter up vertical and lift it out of the way.
#4 ALIGN THE PIN
Once you have cleaned and reoiled your filter it is time to fit it back to into the motorcycle. Firstly make sure no debris has fallen into the air box and then hold the filter vertically and place it down into the air box. There is a pin on the back of the air filter that has to align with a hole in the air box. This is the part I see people mess up and get wrong.
#5 STRAP IT IN
Once you have located the pin in the bottom of the air filter with the hole in the air box, lay the filter flat making sure all the sides of the air filter are tucked in and then refit the rubber strap at the top of the air filter.
#6 CHECK YOUR SEATING
Before you fit the air box lid. Check all the sides of the air filter to make sure it is sitting flat and is sealing correctly all over. Then clip the top of the air box cover into place and then lower the rear of the cover down until you feel it click into place.
#7 REPLACE VENT HOSE
Now clip the fuel vent hose back into the air box cover and fit it back into the steering stem.
#8 REPLACE SEAT
To refit the seat section slide the bottom section in first and then lay it into place. Then turn the dzus clip half a turn to the right until you feel it click into place. Then you have refitted your air filter correctly and you are ready to go riding.
For the full feature, check out issue #533 of ADB.