I have a 50hp force that will start just fine but only run 3-4 seconds. I have bought new gas, new fuel line with bulb and checked all the fuel lines to be sure they are not blocked. I have been unable to get the buld to pump up firm and it seems to be just running out of gas after you start it. You can kkep it running longer by manually chocking the motor. Could it be sucking air somewhere like the gas tanks they are plastic tanks and about 15 years old. Thanks for any ideas
