I have a L3130 and never had a Diesel Engine. I am concerned about Fuel Gelling. I don't use the Tractor very often consequently I fill it with Fuel once a year. How can I tell if the fuel has Gelled, when I look at my fuel filter glass bowl there is a white ring on the bottom. Is that a sign that the fuel has gelled. If it has gelled what do I have to do before I try to start the Engine. I did add a additive to the fuel this past summer.