2009 yz450f problem

I just bought this bike 3 weeks ago and noticed that it pops alot when slowing down threw every gear. I was wondering if i can change some jets to make it run a little smoother?

This is my first bike so i would like to get it running top notch.

Thanks everyone

i own the same bike and it has always popped when downshifting and slowing down,i have tryed jetting and still pops,i have rode this bike for 2 years and did not touch anything and when i decided to change piston and rings and valves i did not have to because everything was in specs,great bike and enjoy the best year bike yami ever put out!

The link as for a 2006?

I forgot to add i also have an fmf pipe with megabomb header on it. I also have the red fuel screw on it

what is an fcr carb and an a cv carb?

The Keihin FCR-MX is the carb the '03-'09 450's came with. Slide throttle with an accelerator pump. "CV" carbs (constant velocity) often come on quads, and have a manually opened butterfly throttle valve with a slide throttle in front of that, operated by intake vacuum so the throttle is actually opened by the engine's demand for air.

Why do you ask?

On the link you sent me he mentions an fcr carb and a cv carb

just wanted to clarify what one i had

alright i checked with my fuel screw and i had to turn it like 3.5 turns out to get it to run smooth, So ill be trying 1 size bigger on my pilot jet to see if that helps!

Thanks guys

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