[YFZ 450 air intake mod.] - ATV Riders Forums - Honda, Yamaha, Suzuki, Kawasaki, Polaris, CanAm, Arctic Cat, Kymco ATVs

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YFZ 450 air intake mod.
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Posted by: quadboy-55

heres an intake mod i did recently to my 07 YFZ. it noticably incresed airflow, and is fairly easy to do. it took about an hour and all you need is:

-10ml socket and socket wrench
-Screw driver (+ for removing clamps)
-Dremel with a disk cutter
-Glue gun
-paper towel
-Sharpie or other permanent marker.
-common sence and a set of basic knowedge to get the job done right (LOL)

1. start by removing the seat and the four 10ml bolts holding the air box on. loosten the engine breather from the airbox. loosten the clamp on the intake hose to the airbox. now compleatly remove the airbox.

2. remove the stock air box lid and place it to the side. remove the airfilter and place it in a **clean** low traffic area

Posted by: quadboy-55

3. remove the stock rubber end from the top of the airbox lid, you will need it for later so hang onto it.

Posted by: quadboy-55

4. using the rubber piece, on the back side of the airbox (filter outlet being on the opposite side of you) use the rubber end piece and outline the thin side onto the right side of the part that sticks out. then repeat this step with the airbox lid inlet on the same spot. now you should have two outlines of the same 4 sided shape, one inside the other. refer to the pic below.

Posted by: quadboy-55

without the rubber end piece in the way you can get a better understanding of step 4.

Posted by: quadboy-55

5. use the dremel to cut inbetween, but closer to the inner line. the outer line represents the airea you do not want to go past.

heres after what youre cut should look like.

Posted by: quadboy-55

6. the rubber piece will not yet fit in here yet, so continue fine tuning the cut, by expanding outwards untill you achieve a perfect fit for the rubber end piece.

here is the finnished cut.

Posted by: quadboy-55

7. hot glue the perimeter of the end piece and place it inside the airbox like this. then glue the edges of the rubber end piece so it remains in the box for a long time.

Posted by: quadboy-55

8. for those of you who want to still use youre airbox lid you will find that it blocks just over 50% of youre new hole. what can you do? this! start by installing yorue lid, and through the hole outline the new hole onto the snorkel piece of youre airbox lid like this with a permanent marker.

Posted by: quadboy-55

when you trim the air box lid snorkel it should look like this.

Posted by: quadboy-55

9. when you place youre air box back onto youre quad you will find a number of things. one of them being that a plastic wall is covering 70% of that new hole and that there is no place for it to breathe fresh air. fear not, the next few steps show you how to trim youre plastics for optimal airflow to youre new air inlet.

Posted by: quadboy-55

10. with the airbox back in the quad, but not bolted yet, its time to pull out that sharpie again, and outline (again) on the plastic the same shape of the fresh cut piece. this will open things up a bit again, and move that piece out of the way, but still act as a snorkel to keep unwanted water and track dust out.

Posted by: quadboy-55

11. with that area cut out, solves one dellemma, but brings up a new one, where does the air come fromm? at the bottom of the plastic you will find youre answer. by shining a light from the top casts a shadow you can see from the bottom, trace this with the sharpie about 1/8th of an incha back, to leave room for error. once you have drawn the triangle, cut it out, and fine trim untill it sits flush with all three sides of the triangle.

it should look like this.

Posted by: quadboy-55

12. now, re-install the airbox in reverse order from wich you removed it, making sure all bolts and clamps are tight. but no overly tight. when properly installed the new airbox inlet should sit flush with the cut out area in the plastic that leads to the opening. and the new hole should sit close to the airbox lid hole with kindof a little fin for the air to go both ways.

when you fire it up you should be able to feel it sucking from the triangular hole when you rev the ATV.

here are some aditional pics.

Posted by: quadboy-55

*note, some jetting changes are nessesary after the install of this mod, as it allows noticably more air causing a lean mix.

Posted by: mxpimp2000

nice write up quadboy, now just cut that screen outta the intake and optomize ur flow

Posted by: quadboy-55

yea, i was thinking about doing that untill i can get an FCI.

Posted by: justin1022

nice mod weres that rubberfrom

Posted by: quadboy-55

used to be on the airbox lid.

Posted by: racer 557

justin it even says in the article take rubber off of air lid it will be used later

Posted by: quadboy-55

quote:
Originally posted by racer 557
justin it even says in the article take rubber off of air lid it will be used later

LOL, thanks bro.

Posted by: quadracer55

looks nice, what made you think of this

Posted by: quadboy-55

MXpimp2000 did a similar mod on his YFZ.

Posted by: mxpimp2000

quote:
Originally posted by quadboy-55
MXpimp2000 did a similar mod on his YFZ.

Posted by: kyledvor61

Also, you can drill holes in the airbox lid, or take the lid off.

Posted by: quadboy-55

quote:
Originally posted by kyledvor61
Also, you can drill holes in the airbox lid, or take the lid off.

my set-up is running with the lid off. the problem you encounter with no lid is the seat sits really close to the airbox anyway that you "really" dont gain that much performance out of it.

mods like mine, and mxpimp's gather extra air from a custom drilled out hole elsewhere in the airbox with its own intake hole.

heres an interesting fact i encountered to prove the capacity of this mod. after it was all done: if you place your hand by the hole in the rear plastic where it draws its air under the quad, you can feel it suck noticable ammounts of air, and thats with the airbox lid off aswell.