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Airbox mod

Posted: June 27th, 2008, 5:11 am
by eyesky2002
Ok kids... I am stuck on my airbox!

My frame is a 03 CRF450R, using the stock airbox and boot. Length was great but I was unable to get it to stretch over the carb with heat; ended up tearing the boot.

Tried the 98-99 CR250 boot as stated by some, length was great, fit on the carb; but the back end of the boot sat to low to mount to the 450 box or use the CR250 filter and mounting ring.

Should I try the stock CR500 boot.

How about a different year CRF450 boot, so any of those have a larger carb intake?

I have even thought about vulcanizing both boots together to make one, but know that is an engine failure waiting to happen if they come apart....

Needs some suggestions, show me what worked for u, nice pics help!!!

Posted: June 27th, 2008, 7:31 am
by dannygraves
On my gen-4 I'm doing like Bob did. gen2 250 airboot and a peice of lexan plastic with the boot hole cut out.
Look at Bobs to see what I am talking about.

Posted: June 27th, 2008, 2:39 pm
by aloha450x
i used the sytock 450 boot. the carb was turned and had a bit of material taked off the boot side. i heated the boot with a hairdrier and used a litte wd40 and she slid right on. ill post pics this evening. after it was on and cooled i heated it and let it cool. i did this several times to allow the boot to mold to the new size. http://www.bannedcr500riders.com/board/ ... php?t=3286

Posted: June 27th, 2008, 6:52 pm
by iggys-amsoil
Although not a 450, I take the airbox loose from the subframe, get the boot on carb, tighten the clamp, reattach airbox. :idea:

Posted: June 27th, 2008, 9:35 pm
by nmdesertrider
mine was off by a 1/2 inch, so i used a peice of 2inch pvc and a 2 inch rubber coupler to create and extension.
I widened the hole in the 450 airbox and pulled a 2001 airbox through the hole.
You won't notice anything different unless you look closely.

Posted: June 27th, 2008, 10:45 pm
by Ported&Polished
Or just get some black duct tape, some shoe polish, a shop rag, and a staple gun and do it right! :D