Were you able to repair with the filter change? There is another filter inline with the LP supply line to the mixer. It is a cylindrical filter that becomes easily clogged. Need to replace. Should it still be hard to start, need to complete fuel pressure checks, solenoid checks and possibly replace the injector at the base of the mixer. This system was the first attempt at meeting stronger emission restrictions. The regulator has two solenoids, one for initial start and one for maintaining RPM range of the engine. Thanks.