04 WR450F airbox mod

[Mats]

Okay so far I changed the exhaust insert and the throttle stop on my 04 WR450, but what do I do with the airbox and jetting?

Airbox: There is some kind of snorkel in the box, should I remove that one?

Jetting: Going with stock, should I change?

Greatful for help,

Mats

[chipwich]

use a flathead screwdriver to pry it away from the strap side while pulling it out at the same time. very easy.

do a search for more detail

[Maddog542]

There are also 2 cutouts under the right side plate that you can use to increase airflow, in addition to, or in lieu of the snorkel. I left the snorkel in place and used the cutouts. As for jetting, JD told me that using the stock jetting kit, you would raise the needle 1 position, and increase main jet by 2 sizes. My other personal recommendation would be that while you have the carb off, install the Zip-Ty fuel screw for easy adjustment. For optimum jetting, I'm sure the JD Jetting kit supercedes stock, but mine rips right now the way I have it setup, with no stumbles, bogs, or hesitation. If you do the airbox mods without jetting changes it will fall on it's face with a bog from hell ?, so prepare to do it all at once.

[YamahaWR450FMike]

There are also 2 cutouts under the right side plate that you can use to increase airflow, in addition to, or in lieu of the snorkel. I left the snorkel in place and used the cutouts. As for jetting, JD told me that using the stock jetting kit, you would raise the needle 1 position, and increase main jet by 2 sizes. My other personal recommendation would be that while you have the carb off, install the Zip-Ty fuel screw for easy adjustment. For optimum jetting, I'm sure the JD Jetting kit supercedes stock, but mine rips right now the way I have it setup, with no stumbles, bogs, or hesitation. If you do the airbox mods without jetting changes it will fall on it's face with a bog from hell ?, so prepare to do it all at once.

question about the jetting? I bought my WR450 bran new in April. Got 400 miles on it so far. Never have had to mess with the the jetting it's stock and runs great. Just wondering why so many people on the forum are changing the jetting. Mine is just fine stock.

[Top]

Maybe you have a dealer that knows how to set a bike up???? ?

[Treebark]

When mine was new I had to increase the main jet to a #165 with the stock muffler and airbox mod. I never had to mess with the fuel screw until recently when I installed a powerbomb.

[r_dawg1021]

My '04 was horrible off out of the box. After taking the cork out and throwing the zip-ty on I can't keep the tire off the ground. ?

[Maddog542]

Mike,

Mine was good out of the box also when I had only done throttle stop, grey wire, GYT-R insert, or even uncorked it was fine. When I did the cutouts on the airbox, I had to rejet. I'm at a #170 main now with the needle raised 1 position, and it runs supreb. I can hardly see how one could do any airbox mods and stay with stock jetting without running her mighty lean and mighty hot.

[NewfieWR]

Mad Dog;

What altitude are you running ??? Was the difference in pwer much greater ???

[av8shunmeckaneck]

There are also 2 cutouts under the right side plate that you can use to increase airflow, in addition to, or in lieu of the snorkel. I left the snorkel in place and used the cutouts. As for jetting, JD told me that using the stock jetting kit, you would raise the needle 1 position, and increase main jet by 2 sizes. My other personal recommendation would be that while you have the carb off, install the Zip-Ty fuel screw for easy adjustment. For optimum jetting, I'm sure the JD Jetting kit supercedes stock, but mine rips right now the way I have it setup, with no stumbles, bogs, or hesitation. If you do the airbox mods without jetting changes it will fall on it's face with a bog from hell ?, so prepare to do it all at once.

bog from hell??? thats what i have. Maybe while my bike is apart right now i should change some stuff up. thanks.