I have a exmark z hp mower with Kohler engine, its a 2003 model and has given me no promblems for the 13 years I have owned it until today, It stalled while running, it will restart but will only run with the choke on, it seems to be starving for gas , so I replaced the fuel filter, and didnt work, checked the air filter and its clean, my only thought might be fuel pump, how would I check this? its getting some gas because it will run, but only with choke on, its 80 degree here in Texas today, Thanks Gary in Texas