Ok DD here are the skinnys on fuel filters..
They will allow full flow when new. As they grow older and began to fill with JUNK they allow less and less flow. Then they start not allowing enough to stay at hiway speed...In efect you appear to "run out of fuel" at 60mph but you can drive at say 50mph and all is good.
so if you are experiencing a similiar problem to what I described you may have a clogged filter.
I do not know your zact setup. But filters are commonly between the pump and the carb. This could be on top of the engine or under the vehicle attached to the frame or inside the fuel tank.
The filters inside the tank are on the intake side of the pump in there.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />