My J-red 2159 has always leaked a little bar oil when it's stored but I didn't realize how much until I bought a nice storage bag for it, I needed it over the weekend and it must have leaked a full tank of bar oil into the bag. Are there any common reasons it would be leaking? It's done it since new so I doubt the tank is cracked, would a bad pump cause this? Saw is probably 6-7 years old but hasn't seen much use.