Fuel and Water Sensor 8M0021043 8M0214989 889330 for Mercury Mariner 75-400 HP Verado DFI
Fuel and Water Sensor 8M0021043 8M0214989 889330 for Mercury Mariner 75-400 HP Verado DFI
Product Overview
Fuel and water sensor for Mercury and Mariner outboards from 75 HP to 400 HP and for the MerCruiser ZEUS DRV 3000 stern drive. It replaces Mercury 8M0021043, 8M0214989 and 889330, and it is the probe that sits in the fuel filter bowl and signals water to the engine management system.
When water sits in the bottom of a fuel filter, this sensor trips the water in fuel warning on the SmartCraft gauge. A failed sensor either keeps the warning on with a clean bowl or, worse, stays silent while the bowl fills, which is how a set of injectors gets destroyed on a DFI or Verado motor.
It fits the three cylinder DFI family at 75, 90, 115 and 125 HP and the 80 Jet, the four cylinder Verado at 135, 150 and 175 HP, the 3.0 L DFI 200 and 225 with DTS, the six cylinder Verado from 200 PRO to 400 HP and the MerCruiser ZEUS pod drive.
Specifications
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Fuel and water sensor |
| Position | Fuel filter bowl, water in fuel probe |
| Connection | Plug in, original harness |
| Country of Origin | Taiwan |
| Net Weight | 75 g including packaging |
| Pack Size | 15 x 10 x 5 cm |
OEM Cross Reference
| Brand | OEM Part Numbers |
|---|---|
| Mercury MerCruiser | 8M0021043 |
| Mercury MerCruiser, alternate | 8M0214989 |
| Mercury MerCruiser, short number | 889330 |
Compatible Engines
| Model | Horsepower | Layout |
|---|---|---|
| 75 DFI | 75 HP | 3 cylinder, 1.5 L |
| 80 Jet | 80 HP | 3 cylinder, 1.5 L |
| 90 DFI | 90 HP | 3 cylinder, 1.5 L |
| 115 DFI | 115 HP | 3 cylinder, 1.5 L |
| 125 DFI | 125 HP | 3 cylinder, 1.5 L |
| 135 Verado | 135 HP | 4 cylinder, 4-stroke |
| 150 Verado | 150 HP | 4 cylinder, 4-stroke |
| 175 Verado | 175 HP | 4 cylinder, 4-stroke |
| 200 DFI DTS | 200 HP | 3.0 L |
| 200 Pro Verado | 200 HP | 6 cylinder, 4-stroke |
| 225 DFI DTS | 225 HP | 3.0 L |
| 225 Verado | 225 HP | 6 cylinder, 4-stroke |
| 250 Pro Verado | 250 HP | 6 cylinder, 4-stroke |
| 275 Verado | 275 HP | 6 cylinder, 4-stroke |
| 300 Pro Verado | 300 HP | 6 cylinder, 4-stroke |
| 350 Pro Verado | 350 HP | 6 cylinder, 4-stroke |
| 400 Verado | 400 HP | 6 cylinder, 4-stroke |
| MerCruiser ZEUS DRV 3000 | Stern drive | Pod drive |
What's Included
| Component | Detail | Qty |
|---|---|---|
| Fuel and water sensor | 8M0021043 pattern | 1 |
| Filter bowl and element | Not included, order separately | 0 |
| Sealing ring | Not included, reuse the original | 0 |
Water in Fuel Warnings
| What the Gauge Shows | Most Likely Cause | What To Do |
|---|---|---|
| Warning on, bowl visibly clean | Sensor fouled or failed | Clean the probe, renew if it stays on |
| No warning, motor misfires | Sensor dead, water in the bowl | Drain the bowl and renew the sensor |
| Warning comes and goes | Water sloshing, drain not done | Drain the bowl and check the source |
| Warning after refuelling | Water from the marina tank | Drain, treat the fuel, check the sensor |
| Corrosion on the plug | Water past the bowl seal | New bowl seal with the sensor |
| Warning with a new sensor | Harness fault, not the sensor | Check the plug and the ground |
Why Water Matters on DFI and Verado Motors
| Engine Type | What Water Does | Service Practice |
|---|---|---|
| DFI and OptiMax | Water reaches the high pressure pump | Drain the bowl every fill, carry a spare sensor |
| Verado four stroke | Injector tips corrode | Drain the bowl, keep the filter fresh |
| 3.0 L DFI | Hard starting and a miss | Check the sensor at every filter change |
| MerCruiser ZEUS | Sensor fault sets a fault code | Renew with the filter service |
| Boats left in the water | Condensation in a part full tank | Keep tanks full, drain the bowl monthly |
| Ethanol blend fuel | Phase separation puts water in the bowl | Test for phase separation, do not run it |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Check the number on the old sensor, 8M0021043, 8M0214989 and 889330 are the same probe |
| 2 | Key off, the SmartCraft system stores a water in fuel fault once the probe is unplugged |
| 3 | Drain the filter bowl into a clear container and look for the water line |
| 4 | Unplug the connector, release the retaining clip and lift the probe out |
| 5 | Clean the bore, fit the new probe with a new sealing ring |
| 6 | Plug in, run the motor and clear any stored faults on the gauge |
| 7 | Refill the bowl and prime before starting |
| 8 | Run and check the warning stays off with the bowl full of clean fuel |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Sealed retail packaging |
Before You Buy
- Check the number on the old sensor, 8M0021043, 8M0214989 and 889330 interchange
- Fits Mercury and Mariner 75 HP to 400 HP DFI, OptiMax and Verado outboards
- Also fits the MerCruiser ZEUS DRV 3000 stern drive
- This is the sensor only, the filter bowl and element are not included
- Drain the bowl and look for water before blaming the sensor
- Always fit a new sealing ring with the probe
- 30-Day Easy Returns
- Ships from our warehouse with tracking
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Boat Owners' Review
Before You Buy
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