If it has a pump it is usually a vacume system. it will be up by the top of the engine, a vacume pipe will run to the rocker box, or crackcase from the pump the feed pipe will come from the tank, and the feed pipe will run to the carb, if the tank is at the rear of the tractor, or there is no gravity feed from the tank it will have a pump, and inline filter.
Husqvarna man, April 2010