2006 YZ450 Flaw?

Today we were at Clear Creek. It was snowing off and on, a lot of standing water and our bikes got really wet. My partner and I both have 06 yz450's and we both had problems with our bikes today? When rolling off the throttle the bike would pop and the engine would die? If you kept reving it it would stay lit but, popping and bogging the entire time. Now I;ve owned about a dozen motorcycles in my career and water has never been a factor with something like this unless of course you drop it it the river. I have re jetted to a 48 pilot jet and have the boyeseen acc pump cover. Is there a flaw in the bike? Has anyone else had this problem?

Sounds like you need a fuel screw adjustment.

We'll I have an STR fuel screw and tried adjusting it but with no success? If it was the fuel screw adjustment why would it run above 1/3 throttle flawlessly?

Because the fuel screw has very little effect above 1/4 throttle. Once you get above 1/4, you are into the main and needle. Hope this helps.


If it was the fuel screw adjustment why would it run above 1/3 throttle flawlessly?

Because at 1/3 (and up) throttle your carb uses the needle and main jet. At low speeds your pilot and fuel screw are in control.

HEY!!! That is what I said!! Get your own answer. LOL

Aren't we a bunch of brainiacs!!


okay so do i adjust it out or in?

well it sounds to me like its too lean so richen her up a bit and you'll be fine

Out is richer, in is leaner. Adjust it until you don't have the popping any more. 1/8 to 1/4 turn at a time and then do a test run. If you end up with the fuel screw out more than 2 turns go to a bigger pilot and start over again with the screw. In more than 1 or 1/2 turns than time for a smaller pilot. Hope this helps.


probably got a lot of water in the airbox and filter. Thus water does not burn, so you need to keep the rpms up to keep it running.

Bet you dry things out, install a new clean filter and the bike runs like a champ again.

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