Although there is no prescribed interval (that I could find in the Onan manual), it is probably good preventative maintenance to change the LP fuel filter on the Onan Marquis generator that comes standard on the D. Before replacing filter, SHUT OFF THE GENERATOR PROPANE FUEL SUPPLY AT THE TANK. The Tank is in the center of the chassis (front to rear & side to side); you have to crawl under the D to get to it. Shut off is on curb side of tank.
You must remove the filter & solenoid assembly, which can be reached through the hood opening. It is right where fuel line from the LP tank ends on the street side of generator. Remove the LP fuel line from the tank and from the solenoid to the generator, then remove the two screws from top on mounting. Leave solenoid and filter together. Remove cup from filter for access to media. Replace media and seals with Onan kit parts. Do not remove center post; it is a magnet.
(NOTE: The fuel filter kit is available at your Onan dealer for about $17)
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