HI, I HAVE A RANCHER 350ES AND IT IS SUCKING OIL FROM THE ENGINE INTO THE AIR BOX.ITHINK IT IS THE VALVES BUT I AM NOT SHURE.THANKS

 

Are you sure it isn't just oil dripping down off of your air filter?!?!? If you put too much oil on them some will leak off. I always have a bit of oil in my airbox from drip-off.

 

Do you have a K&N filter or foam?? My 4X4 Rancher has a K&N, and by the time the filter is dirty enough to change, it has a bunch of engine oil on it (it covers about 1/4 of the outerwears)! The 2X4 still has the stock filter on it, and I don't particularly notice any extra oil on it, but it may be that it just doesn't stand out on the foam. Also, do you ever tip you bike up on the rear rack? That can do it too.