88 Mighty Max Fuel Supply From Tank Question

[pandemic326]

I just want to verify that the supply to the carb from the tank is the hose coming out of the top of the tank that feeds into the factory filter on the little bracket? Doing a Weber swap and an electric fuel pump install and want to make sure I’m not being an idiot.

[Law Dog]

Sounds right figure what pressure you will end up with at the Webber if you go with electric pump. I put a pressure regulator on mine with the regular stock pump never had any issues.

[pandemic326]

Using the pump geezer recommends so sends ~3psi. After no luck still pressurized my gas tank and seems what I thought was the return was the supply which seems to trace back to one of the lines going in on the side of the tank by the filler neck. Went and looked and what I thought was a small fuel filter really seems to be a check valve. Arrow that I thought was a flow direction really must just be pointing toward carb as the flow direction is opposite. Pulled a part number off it and googled and came back to a fuel vapor line so guessing that in fact was the return. So flipping some lines and retesting. Trying to have the fuel line primed to the pump so I don’t burn it up.

[Law Dog]

Gas filters on most of them are plastic and clamp on near the fuel tank. Go to rock auto like your looking for one to buy it they should show a photo of it there.

[SubGothius]

On that type of filter, the top barb should be output to the carb, so the lower barb on the side would be intake supply from the tank. Typically you'd want a filter before the pump, but I prefer to have a wire-mesh strainer filter before the pump (e.g. Wix WF10461) along with a post-pump regular cellulose filter in a transparent plastic housing underhood near the carb where I can easily inspect it.

Not quite sure I followed what you meant about the arrow and flow direction, as the arrow on a filter or check valve should always point in the direction of flow -- i.e., for a check valve it should not be possible to blow through it against the direction of the arrow. If that was on the vapor line, that may be a two-way valve that vents positive pressure from the tank to the charcoal canister underhood, but negative pressure (vacuum) from the tank (e.g. as the tank empties, or fuel cools down and contracts) would draw ambient air through another opening on the valve; as such, there may be more than one arrow to indicate which barb is which.

[pandemic326]

Thanks everyone. I got it all worked out the the pickup fired up. Really appreciate the help.