I am having a problem with my SRM-210 - It doesn't seem to be getting fuel. The primer-bulb does not fill up with fuel when pumped. When I pump the bulb, it blows fuel out of the check valve. When I take the carb apart and operate the bulb, it squirts fuel seemingly normal through the metal plate into the diaphragm. The fuel lines are clear and the filter is new. Any ideas? Thanks.