Fuel Pump Question

Some folks mistakenly think that partly large, and partly small line restricts the flow to the "smallest" standard. This is not true for two reasons

1....In this case the large line is on the suction/ low pressure side of the pump. That is where larger line would do the most good, as restrictions in the low pressure side ESPECIALLY in a suction line make much more difference than on the higher pressure outlet side

2....The smaller line is not very long. FRICTION is what matters there, as the line is much shorter, as well as higher pressure, so the effect will be minimal