I have a carb out of a 99 Artic Cat 300 4x2 that is overflowing as soon as i turn shut off valve on. I've replaced the float and needle valve and it's still overflowing. Does anyone have any suggestions as to what's going on.

 

It seems strange that it would overflow if the settings are correct. I had mine due the same thing and it was a small piece of dirt that kept the needle valve from seating correctly. Make sure the needle valve seat is not damaged, dirty, or pitted, which would keep it from seating and shutting off the gas.

 

this might helpo
take the carb out...
take off the float and valve

pop out the "Great big ole" jet the flat/needle vale sits it it's about .4 in diameter, and has orings and a screen...

look at all the CRAP under it... blow it out, dunk it in carb cleaner, boil it, blow it out again, and put an inline fuel filter on.