Use Pressure Gauge, Part No. ST-1273, to measure fuel drain line restriction.
NOTE: Do not measure fuel drain line restriction with the fuel measuring device installed. This will not measure the
drain line restriction of the vehicle’s return plumbing.
Hold the gauge at the same level as the connection.
NOTE: The gauge will not measure the correct pressure if the gauge is not held at the same level as the connection.
Operate the engine at maximum horsepower RPM and Advertised Horsepower.
Observe the reading on the gauge.
NOTE: The maximum fuel drain line restriction for STC and CELECTTM is as follows:
With Check Valves: 165 mm Hg [6.5 in Hg]
Without Check Valves: 65 mm Hg [2.5 in Hg]
