fuel filter

[Doc in Vermont]

Are there any precautions to take when changing out a fuel filter?

[Pammark]

It depends on what type of fuel filter you have.

If it is gasoline, not much. If gravity feed to the carb, I like to loosen the fuel fitting at the carb until it pisses a good stream to get most of the air out. Make sure you install the filter in the correct direction of flow, if there is an arrow indicator.

For diesel, you do not want to get air in the system. Take the new filter cartridge and fill clear full with new fuel. Screw on the base carefully. Some systems have a hand primer pump to open and push out the air. Start the engine. If it dies from air in the system, you have more work ahead. Air is compressible so a bubble might sit in a fuel injector line (air lock) without passing into the combustion chamber. I take one or two injector lines at the injector side and crack open so slightly. Crank the engine until you see a good spray of fuel from the loose fitting. Tighten, and the engine should run on one or two cylinders until it purges out the other injectors. If still not running correct, start over with pumping the primer. Oh, it is nice to have fuel in the tank too.


Mark

[Doc in Vermont]

Thanks for your help. I think I have air lock.