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H2F-FCU38RM Micro Fuel Flow Meter Installation Guide

Product Information 

  • Designed to be fitted into the fuel line to display fuel flow per minute and total litres used

  • Please note all 3/8" models are normally only suitable for up to 85-95 HP outboards

Fitting Recessed Display 


  • The LCD Polarised Display on the H2F-FCU38RM Micro Fuel Flow Meter is designed to be only visible when viewed from horizontal and below.  When viewed from this angle the display is extremely clear

  • Using the display as a template mark out hole and cut to suit

  • Fix in position with bolts provided or suitable screws

H2F FM Viewing Angle.jpg


Connecting Sender Unit  (refer diagram below)

  • The sender unit must be installed in the horizontal position

  • The thread specification of the sender unit is 3/8" Barb 

  • Make sure the sender is fitted with the fuel flow in the direction of the arrow noting that

      flow direction is one way

  • Connect directly with a 3/8" hose, noting that hose clamps should always be used to secure the connection

  • The display comes pre-wired with an approximately 1.4m sender cable  

  • Extra 1.4m & 3m extension leads are available for the three pin plugs

  • Up to 6 leads may be joined to make 9.8m in total length

  • Please Note:  Sender leads cannot be cut and joined – this will void your warranty, extension leads must be  used


Connection to 12Volt DC Adapter


  • It is recommended that you get the 12v power from the pump circuit

  • Simply cut off the two pin 12v plug to the required length and connect the black wire to the negative terminal and the red wire to the positive power source

  • The back-light will stay ON when connected to 12v

  • All settings and amounts will be stored if power is disconnected


Current use at 12Volt DC Adapter

  • 1 mA when operational

  • 0.015 mA when asleep 

  • Please Note: 1,000 mA (milliamp) = 1 A (amp)

Programming & Display Selection

  • Press "DISPLAY" button to turn display on the screen

  • To set the Display for the 3/8" sender supplied you will need to press both buttons at the same time & release.  "H34" is the setting that you need displayed

  • If "H34" is not displayed, continue to press and release the "DISPLAY" button until "H34" is displayed

  • Press "DISPLAY" button again, this will display the accumulated flowing volume (flow totalisation) or real time flow rate

  • Press and release "RESET" button for four seconds which will reset the total measuring volume to zero

  • Please Note:  The maximum monitoring capacity is 99,999 litres


  • The Topargee H2F-FCU38RM Micro Fuel Flow Meter will automatically turn on when there is fuel flowing through the sensor 

  • It will automatically turn off 10 seconds after there is no fuel flowing

  • Blue back-light remains on unless a switch is fitted in power line


  • Press and hold the "RESET" button for 4 seconds

  • The total measuring volume will be reset to 0


  • ​Colour                              White

  • Power                               12 Volt DC

  • Mounting                           Recessed Mount

  • Screen                               LCD Polarised Display

  • Sender Lead                       1.4 Meters

  • Ext Lead Option                  Yes

  • Connection Size                  3/8” Barb

  • Flow Rate                           0.05 - 1 LPM (3-60 LPH) when fitted after the fuel pump (pressure side)

                                               0.05 - 0.60 LPM (3-36 LPH) when fitted before the fuel pump (suction side)

  • Flow Rate Display                LPM & total amount

Please Note: flow will be restricted if maximum flow rate is exceeded.  Check BEFORE purchasing / fitting.  It is recommended that a 50 micron filter is fitted before the flow sensor

  • Pressure                              Max 6 bar (85 psi)

  • Temperature                         0 to 60℃ (32 to 140 ℉)

  • Suitable for Fuels                  Yes  (fuel, diesel & petrol - noting will not measure diesel return line to tank

  • ​Suitable for Water                Yes

  • Displays Litres or Gallons       Yes

  • Weight                               140 g (5.38 oz)

  • Accuracy                             +/- 5%

  • Materials                             Sensor Body - PA66 with 50% glass fibre,  Grivory - GV-5H

                                                Turbine - Acetal Copolymer, TICONA - M90

                                                Shaft of Turbine - #304 Stainless Steel

                                                O-Ring - NBR

                                                Rubber Housing - ABS resin


Please Note: Due to continuous product improvement, specifications are subject to change without notice

Downloadable Installation Guide

H2F FM Dimensions.FS.jpg
Flow Sensor 38 Measurements.jpg
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