I put in a new idle jet and cleaned the carb on my 2000 yz426. Put it all back together and now it leaks gas as soon as I turn the gas on. Float is not sticking and float level appears to be correct. I took the bowl off and hooked up the gas to the carb then pushed the float up to the position it would be in if it was floating in gas with the bowl on, then turned on the gas, and gas was still coming out of the needle valve/seat area. The o-ring on the seat looked pretty flattened out...not cracked, but appeared to be almost flush with the rest of the seat. I noticed the seat almost felt loose when I put it in the carb body (without the retaining screw attached). Am I correct in assuming its either the needle valve or the valve seat o-ring that is the problem?