I have had leaking fuel at the float needles many times over the years on my Honda xr400r and trx400ex bikes. Recently on my xr400r the problem continued intermittently over the course of a year before I found the actual problem. My petcock had previously failed and left some little pieces of debris in the fuel line at the float needle. Sometimes the debris would get stuck under the float needle and other times it wouldn't. Now when I remove the float needle I always blow compressed air from the float needle inlet backwards out through the fuel supply hose, which I disconnect at the petcock, to make sure there is no debris in the fuel supply.
danryan92468 commented on grayracer513's article in ArticlesWill the octane level diminish over time as gas sits unused in a gas tank?