Airbox holds battery

There is no way you can cut out the amount of material that is shown in the airbox cutout diagrams, what the heck will hold the battery, it rest in the square section. I can't see how removing the snorkle would do anything either, there is some material that can be cut. Anyone have pics/proceedures of the airbox cutout for a CRF450X?

Cut the plastic part of the air box, not the metal bracket that holds up the battery.

Doh... :thumbsup: my bad, I ran inside to my PC to redeam myself after noticing the metal bracket. Seriously, is it worth it, how does the air get around the battery and such. trying to see the air flow pattern here. basically I see a small opening between the rear of the gas tank towards the left of the bike for air to pass through, no sure how cutting the airbox would do anything. Plus the opening of the carb is not as big as the snorkel opening. What's the logic here?

Cut the air scoop vents on the side plate's.

Where is that?

Doh... :thumbsup: my bad, I ran inside to my PC to redeam myself after noticing the metal bracket. Seriously, is it worth it, how does the air get around the battery and such. trying to see the air flow pattern here. basically I see a small opening between the rear of the gas tank towards the left of the bike for air to pass through, no sure how cutting the airbox would do anything. Plus the opening of the carb is not as big as the snorkel opening. What's the logic here?

As far as ive been taught, the idea here is to equalise pressures between the exhaust and the intake to allow a better balance between the 4 strokes of the motor. If this is true, cutting the airbox will only really come to benefit if you have a free-er flowing exhaust ie. most aftermarket ones. If you have the stock exhaust on, honda went to great lengths to get these balances right( also explains that bloody loop on the header - increase back pressure and therefore low end torque). I could be quite wrong with all this, im not a mechanic. Comments from guys in the know?

The path of least resistance. The smaller the hole the harder the motor has to struggle for air. To prove the point honestly, not being demeaning take a straw and suck air threw it. Then cup your hand around the straw and suck air. You will truly see the difference.

As far as ive been taught, the idea here is to equalise pressures between the exhaust and the intake to allow a better balance between the 4 strokes of the motor. If this is true, cutting the airbox will only really come to benefit if you have a free-er flowing exhaust ie. most aftermarket ones. If you have the stock exhaust on, honda went to great lengths to get these balances right( also explains that bloody loop on the header - increase back pressure and therefore low end torque). I could be quite wrong with all this, im not a mechanic. Comments from guys in the know?

Hes right dont cut the air box :thumbsup: (under seat) unless you put a after market exhaust on :bonk:

How bout the E2 then, it seems the best for CA, I am affraid of the noise and spark arrestor Nazis, even though we ride in the middle of freakin nowhere in the desert. I have decided to pull the snorkel and cut the two side vents, that should be plenty and much more that stock, plus colder air from the sides vs. hot air off the engine.

If you read the J.D. instructions they say you MUST cut the air box for their stuff to work right, I was too chicken to open up the side vents so I just cut the top off, seems to work really well with the recommended J.D. settings.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now