Hello! I have a 2008 DF 50 that had a new power head put on because of piston failure. I'm not a mechanic so not sure of specifics with what went wrong I just know it was bad. I've used the new motor around ten hours and it is stalling periodically like it did on the old motor before it died? It starts back up after I pump the gas ball a few times. I think it has to be something with the fuel. I siphoned out gas and filled with new, treated with Sta-bil, changed water fuel separator, and still stalling. It stalls maybe 3 times an outing and then seems to run fine for the most part after. Could it be a fuel pump or whatever sucks the gas into the motor? Thanks for the help.