Just wondering if these 2 filter types can be used interchangeably on gravity fed fuel systems and if one tends to filter finer particles than the other. Also, do the screen types have a direction of flow or can they be used either way..
May have good fuel flow with the paper filter with the engine not running, but when running below a 1/4 tank with the slight vacuum created by the fume recovery system can cause fuel flow issues to cause fuel starvation. Been there a done that. Used to use the 691035 filters on everything without issue including gravity feed but have encountered issues using that filter with the tank vent to air filter intake type EPA emissions recovery.I've ran the paper type probably same as your picture with no issues on gravity tanks. That red 150 micron Briggs style, yup logs and bricks might be stopped.
Test the paper type on a gravity carb. Simply remove the fuel line AT the carb. See how much go-go juice comes out. These engines don't require a lot of fuel. Just keep the bowl full.
The red filter will allow small sand particles to pass which can and will prevent the float valve from sealing. the white filter works fine on gravity feed systems, and is standard equipment on several mowers with gravity feed.Thanks for the replies. I didn't realize the white pancake style was different from the red. Interestingly, Briggs and Stratton's 75 micron white one recommends it only be used with a fuel pump system.
I ran the paper filters on all riders regardless of fuel flow type. Starting in 2012 with the vacuum vapor line on the top of the tank is when my customers started having running issues with low fuel tanks. Fuel just doesn't like to flow through the 40 micron paper filters when there is a slight vacuum on the fuel tank and no fuel head to push the fuel down the fuel line and through the filter.None of my "mature" Snappers have any EPA nonsense on them. Never had an issue with the paper filters. Ran them on Toro Super Recyclers and Snappers. I see what you mean with the emissions junk causing fuel flow.