Aloha all from Hawaii. Have some fuel problems. Have a Kohler 23hp Commander. Before starting, fuel filter 3/4 full. Starts right up and runs until fuel filter is almost empty. Engine starts to surge until I move the choke up a little then starts running smooth. Cleaned gas cap, changed fuel filter, blew all lines clear, tank to filter, filter to pump and pump to carb. Also, blew a little air thru pump and all clear. Took apart carb, cleaned float area, needle valve and blew all jets. Fuel solenoid also works. Could pump be going out cause not pulling fuel from tank? Need some input....thanks