Ive got an 04 kx 500 that is leaking fuel intermittintly through the overflow tube. Its not like the float is stuck and its powering out nonstop, it just leaks a little here and there. Sometimes a few drips sometimes a 1-2 second leak. It does it sitting and I notice when I stop while riding out on the trail as well. As I said its very random and sometimes its nothing. I am going through more fuel than usual though. I was thinking its prolly the float valve. It is 8 y/o and the valve has a rubber tip that could have some micro cracks in it. What do yall think?

Maybe float level is just a little off, or there is a little piece of junk in there that gets moved around so your issue is intermittent, or as you said the float needle valve is old.

I personally do not worry much about a few drops here and there, but if you are really getting a lot less gas mileage, then a good carb cleaning and checking of your float level is probably in order.

Replaced the float valve and seems to be working good.

May I ask where can I avail a oem carb repair kit for a 04 kx 500? My cousin is having hard time to find one. I hope some one could help out.

Don't know about a complete kit. I just ordered needed parts from dealer