Fuel lines and tap settings International 484

To answer your fuel tank/line question:

The fuel tank is like an upside down U or saddle tanks as they are sometimes called. The purpose of the line between the sides at the bottom is to equalize the fuel level in both sides of the tank as the only time the fuel will flow between the tanks is when it is filled above the level of the top of the U. The line that goes forward from the bottom right (looking from rear) is the fuel feed line that goes to the input of the primary fuel filter. Depending on the year your 484 was made you may have two small CAV type fuel filters on the front right of the engine or one large fuel filter with a drian tap on the front left of the engine.
The line that goes from the bottom left of the tank forward is the fuel return line from the top of the injectors. This returns unused fuel from the injectors back to the fuel tank.

Re shutoff valves, I believe they are screwed counter clockwise to shut off the fuel flow. This means the there is more of the shaft of the T shown when they are shut off.

Here is what happened to my brother's 684:
Every so often it would loose power on a hill or sometimes the engine would die, if you let it sit for 5 minutes away it would go again till next time. So finally last fall he took the line off at the bottom right tank and proceeded to drain the tank. He only got about 1/2 the amount of fuel out of the tank he expected and the fuel guage (only measures in left tank) was still showing the same. He then took the line off the bottom left and there was no fuel flow, took the shut off valve out of the bottom left tank and the rest of the fuel came out. There was a carcus of a lady bug partially plugging the shut off valve in the left tank so when the fuel level would get below the level of the U only the right side of the tank was suppling fuel and occassionly the right side would run dry and starve the engine. Eventually enough fuel would flow thru the partially clogged valve to start the engine again.

Hope this helps JB2