Fuel System Parts - Fuel Tank Gauge Senders

SFW Fuel/Water Level Senders

How It Works
Measurement is done by series of reed switches positioned inside the level tube. A float with built in magnets then triggers the reed relays generating a potential - free resistance with an ohm value that increases or decreases. Resistance output is fully customizable. The float is the only moving part of the sensors, thereby minimizing potential mechanical failures. All sensors are fully insulated to protect against voltage inside the tank.

• Suitable for Gas, Diesel and Water
• 316 Stainless Steel
• SAE 5 Hole Pattern
• Gasket Included
• 240-33 OHMS (240 ohm empty and 33 ohm full)
• Constructed to meet and/or exceed all applicable
• ISO, NMMA/ABYC and USCG standards
• Sensors are fully insulated to protect against voltage inside the tank
• Float is the only moving part of the sensor, minimizing mechanical failure

Sending unit length should be a minimum of one (1) inch less than the plastic tank depth, and three quarters (0.75) of an inch less than the metal tank depth. Note: If metal tank surface flexes, deduct one (1) inch from the depth.

Fuel Level Sender with Return Port

Designed for top mounting in aluminum, plastic or stainless steel fuel tanks in all types of marine vessels. All stainless steel construction resists corrosion and is ethanol compliant. Meets and exceeds current NMMA and ABYC specifications. SS 1/4" NPT female thread with 3/8" barb. 1/4" ground spade terminal. Pre-bent 90 degree float arm.

• 6" to 24" tank depth
• Will not rust or corrode
• Calibrated for 240-33 ohm gauges
  • (240 ohm empty and 33 ohm full)
• Adjusts easily to fit your tank
• Tested to insure accurate readings

Note: Includes gasket and hardware

Adjustable Fuel Level Sender

• For use with 240-33 ohm gauges
  • (240 ohm empty and 33 ohm full)
• Adjustable and can be tailored to most fuel tanks.
• Most common type of fuel level sender in production style boats today.
• Standard 5 Hole mount.
• For Tanks 6" to 24" deep.

Note: Comes With Gaskets

3-Wire Fuel Level Sender 240-33 Ohm

• With a double tube design, these senders measure the amount of air trapped between the tubes providing you accuracy you can't get from float style senders
• For use with 240-33 ohm gauges
• (240 ohm empty and 33 ohm full)
• Will work for gasoline or diesel fuel
• Gasket included
• No mounting hardware included.

*****WARNING NOTE***** Installer error NOT READING INSTRUCTIONS is the number one reason for fuel sender problems and abnormalities. These units require proficient mechanical background to cut, program, and install. These are the best senders on the market and have been in use 30 years. They require proper installation to work.

• NO!  This is a GAS Sender it will NOT read water, or oil!
• NO!  You cannot wire or daisy chain 5 fuel senders together and get one reading
• NO! It reads in OHMS NOT Millivolts, it is NOT digital output 
• NO! It CANNOT calibrate an empty or partially filled tank to a full reading. TANK MUST BE FULL 
• NO! It will not work in your car/airplane with 0-80 OHM gauges these are marine 240-33 OHM senders only.
• NO! It will not defy gravity! If your sender is mounted in the rear of the tank and the bow is in the air it will show more fuel than you have! Boat must be level to earth for accurate reading!
• NO! You do not design your own program sequence you follow the instructions.
• YES!  People have done all of these things wrong...

NOTE: These senders can only be trimmed to a minimum of half their original length, Such as 6" for a 12" Sender and 12" for a 24" sender and so forth. These senders will not work with dual station or two gauges trying to read from one sender. 48" and 60" are made to order and have 3 week lead time.

Note: Includes gasket.

2-Wire Fuel Level Sender 240-33 Ohm

• With a double tube design, these senders measure the amount of air trapped between the tubes providing you accuracy you can't get from float style senders
• For use with 240-33 ohm gauges
• (240 ohm empty and  33 ohm full)
• Will work for gasoline or diesel fuel
• Works with DATCON, LIVORSI (or gaffrig newer than 1996), OMC, STEWART WARNER, TELEFLEX US GAUGE, AUTOMETER, FARIA, and Hardin Marine gauges. Does not work with any digital gauge. If you have a 240-33 ohm gauge that is not on this list you must use 3-wire sender instead.
• Gasket Included
• No Mounting Hardware included.

Note: Includes gasket.

*****WARNING NOTE***** Installer error NOT READING INSTRUCTIONS is the number one reason for fuel sender problems and abnormalities. These units require proficient mechanical background to cut, program, and install. These are the best senders on the market and have been in use 30 years. They require proper installation to work.

• NO!  This is a GAS Sender it will NOT read water, or oil!
• NO!  You cannot wire or daisy chain 5 fuel senders together and get one reading
• NO! It reads in OHMS NOT Millivolts, it is NOT digital output 
• NO! It CANNOT calibrate an empty or partially filled tank to a full reading. TANK MUST BE FULL 
• NO! It will not work in your car/airplane with 0-80 OHM gauges these are marine 240-33 OHM senders only.
• NO! It will not defy gravity! If your sender is mounted in the rear of the tank and the bow is in the air it will show more fuel than you have! Boat must be level to earth for accurate reading!
• NO! You do not design your own program sequence you follow the instructions.
• YES!  People have done all of these things wrong...

NOTE: These senders can only be trimmed to a minimum of half their original length.

These senders will NOT work with digital gauges. These senders will not work with dual station or two gauges trying to read from one sender. They are designed for analog type marine fuel level gauges. Use the 3-wire sender for digital gauge applications.

IMPORTANT: These senders must be re-calibrated if trimmed. THEY DO NOT auto calculate full and empty! See Instructions. The senders auto calibrate to type and grade of gas used.

Fuel Tank Sending Unit

To view and download the PDF instruction sheet CLICK HERE

240 to 33 OMS, Please indicate tank depth when ordering, adjustable float depth 5" to 22". Standard in the industry.

Ultrasonic Tank Sending UnitIndustry standard SAE stud mounting pattern. Supports 10-180, 240-33 and 0-5 volt gauge outputs. Works with Gas, Diesel, Water and Chemical Toilet (Must be programmed to the specific tank) unit programming is completed by IMCO.

Fuel Sender Gasket

• ID: 1.50"
• OD: 2.70"

Replacement Gasket For Use With: 2-Wire, 3-Wire and Adjustable Fuel Level Senders