Hi there. I have a B&S generator Mod# 204412-0156E1 10 HP overhead valves and used it once last year. This year I fired it up and gas was leaking into the carb throat. I rebuilt it and it no longer leaks but the engine will not start. It acts like one of the valves is sticking or is out of adjustmend. It tries to start but won't run. I changed the plug and it gets PLENTY wet so it's not a question of gas. Could the oil safety be keeping it from running? Thanks