I recently bought this used 1988 elite 50, for my daughter to get around with while away at college. it ran very well. then she pulled into a gas station and shot gas in it. soon after it developed a sputtering miss while driving. i´m sure she stirred up dirt and sediment in the tank that created a gas flow issue. now it´s running ok again and nothing was done to it. I´m wondering if there´s a fuel line filter or something on it. I don´t have any kind of manual.