125-200cc Can't stop fuel from coming out float overflow

I have a 2012 cr 144 and gas started leaking out of the overflow a couple of rides ago. I have had my carb apart about 10 times to clean it and adjust the float. I had it stopped before my last ride and it started leaking as soon as I turned the gas on. The carb is stock and had not had any problems. Any suggestions.

Only 3 things can cause it to overflow. 1. Float level to high. 2. Foreign matter trickling thru not allowing needle
to seal. 3. Needle and/or seat bad.

Don't forget too look for hair line crack in brass over flow tube. That has gotten me before. Fill carb bottom when not on carb and let sit for a min.

Check the o ring rubber that is around the outside of the seat needle and seat might be good but the seal around the seat could be bad

I am going to check the overflow tube. I have another carb off of an 09 WR 300 that i have and it did not leak. I changed the float assembly including seat and it still is leaking.

Pull the brass seat assy and check the o rong around the outside of the brass seat not the inside part where the needle goes

I have been having the same problem. Had the carb apart 3 times. Adjusted float level, cleaned, inspected everything. Everything seems fine. Then mysteriously appears again (last night). The next time the carb comes out, it will be collecting dust on a shelf. It's now time to have Kelly resolve the situation this week.

I had this same problem when my '13 was new. I didn't want to chase it for ever, so I just bought a new needle, seat and o-ring. It's been fine for the last 30 hours.

This 0-ring was the issue on a couple of my bikes also ...

a float that won't will do it ever time but thats pretty rare are you bending the little tab that pushes the needle up

Where did you buy the needle, seat, and o-ring?