98 KDX 220 Carb Question

The float needle isn't closing/sealing properly.
A. check your float level.
B. check the float valve needle's tip. It must be perfect.
C. check the needle seat. It must be perfect.
D. check the fuel for particles that will prevent the needle from seating.

Ensure nothing is interfering with float movement. It's not hard to tweak a float if you're hamfisted with bowl attachment.

Burnish the inlet valve.

If this happens only when on the sidestand...your stand is probably bent/worn to the point it just leans over too far.

What does float 'OK' mean? Drop it (lower the level) a couple mm anyway.