'99 yz 400f carburetor issues

Hello everyone, as stated above I have a 1999 yz 400f that I recently bought. I have read a lot of forums about this bike and its carburetor problems and found out that other people have switched their stock carb out for a newer yz carburetor. Would it be possible to use a 2004 yz 450f carb. If not could you guys give me some tips on how to fix my slow throttle response?

Millions of post on throttle response issues for the original FCR MX carbs in the WR and YZ forums.

Basics first.

Disable acc pump and set pilot circuit as per Williams instructions in wr stickies.

Adjust needle next.

Adjust main.

Reset acc pump and adjust stroke/squirt.

Should be good.

No quick fix. You need to be methodical and it will pay off.

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