Water Pump Impeller Kit 6BG-W0078-00 6BG-W0078-01 18-3490 for Yamaha F30 F40 4 Stroke Outboard
Water Pump Impeller Kit 6BG-W0078-00 6BG-W0078-01 18-3490 for Yamaha F30 F40 4 Stroke Outboard
Product Overview
Complete water pump kit for Yamaha four stroke F30 and F40 outboards, the service set with a 55.48 mm impeller that rebuilds the pump in the gearcase rather than just swapping the rubber. It replaces Yamaha 6BG-W0078-00 and 6BG-W0078-01, also written 6BG-W0078-00-00 and 6BG W0078 00 00, and crosses to Sierra 18-3490.
The kit is the sensible way to do a 3 cylinder F30 or F40 pump, because the parts that wear are not just the rubber: the stainless liner cup polishes, the wear plate scores and the plastic housing cover distorts. A new impeller on a worn cup loses flow as surely as the old one did.
The impeller in the kit is the 6 blade type, 55.48 mm outside diameter and 16.10 mm at the shaft bore. The kit is listed against the F30 and F40 from 2009 to 2017 on the international line, and from 2006 on the American F30LA, F30LE, F40JE, F40LA and F40SA models.
Specifications
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Outboard water pump repair kit |
| Impeller Blades | 6 |
| Impeller Outside Diameter | 55.48 mm (2.18 in) |
| Impeller Shaft Bore | 16.10 mm (0.63 in) |
| Materials | Stainless steel, nylon, rubber |
| Net Weight | 242 g including packaging |
| Pack Size | 15 x 10 x 5 cm |
| Warranty | 3 year |
OEM Cross Reference
| Brand | OEM Part Numbers |
|---|---|
| Yamaha | 6BG-W0078-00 |
| Yamaha, superseded | 6BG-W0078-01 |
| Yamaha, long form | 6BG-W0078-00-00 |
| Yamaha, spaced form | 6BG W0078 00 00 |
| Sierra | 18-3490 |
| Impeller inside the kit, old number | 6H4-44352-01 |
| Impeller inside the kit | 6H4-44352-02-00 |
| Impeller inside the kit, alternate | 676-44352-01 |
Compatible Engines
| Model | Horsepower | Years | Line |
|---|---|---|---|
| F30 | 30 HP | 2009 to 2017 | International |
| F40 | 40 HP | 2009 to 2017 | International |
| F30LA, F30LE, F30LEHA | 30 HP | 2006 and later | American |
| F40JE, F40JEHA | 40 HP | 2006 and later | American |
| F40LA, F40SA | 40 HP | 2006 and later | American |
| F30, F40 three cylinder | 30 and 40 HP | 2010 to 2018 | Listed on some listings |
What's Included
| Component | Detail | Qty |
|---|---|---|
| Water pump impeller | 6 blade, 55.48 mm, 6H4-44352-02-00 | 1 |
| Housing cover | Plastic, number not listed | 1 |
| Water pump gasket | Included, number not listed | 1 |
| Insert cup, stainless | Included, number not listed | 1 |
| Wear plate, stainless | Included, number not listed | 1 |
| Water damper seal | Included, number not listed | 1 |
| Bolts with washers | M8, included, number not listed | 4 |
| Woodruff key | Included, number not listed | 1 |
| O-ring | Included, number not listed | 1 |
Why the Whole Kit
| Part | What It Does | If It Is Reused |
|---|---|---|
| Impeller | Moves the cooling water | Set vanes, weak tell tale |
| Insert cup | The stainless liner the vanes run against | Polished cup, flow drops under load |
| Wear plate | Bottom face of the pump | Scored plate, pressure leaks away |
| Housing cover | Top face of the pump | Distorted plastic, water bypasses the impeller |
| Gasket | Seals the housing joint | Air drawn in, the pump loses prime |
| Seal | Keeps water out of the gearcase | Water in the gear oil |
| Key and bolts | Drive the impeller and clamp the housing | Slipping impeller, weeping cover |
Overheat Symptoms on F30 and F40
| What You See | What It Means | What To Do |
|---|---|---|
| Weak tell tale at idle | Impeller set or cup worn | Kit, not just the impeller |
| Tell tale fine at idle, hot at speed | Wear plate and cup worn | Kit with the plate and cup |
| Overheat alarm at low speed | Plastic cover distorted | Kit with the new cover |
| Rubber in the thermostat | Impeller has failed | Kit and flush the passages |
| Water in the gear oil | Pump seal failed | Kit and reseal the gearcase |
| Same fault next season | Worn cup left in place | Change the whole pump, not the rubber |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Check the number on the old housing, 6BG-W0078-00 crosses to Sierra 18-3490 |
| 2 | Drop the lower unit and drain the gear oil before opening the pump |
| 3 | Note the order of the cup, plate and housing as they come apart |
| 4 | Clean the pump body and check the driveshaft for wear under the impeller |
| 5 | Fit the new cup, plate and gasket dry, no sealant |
| 6 | Grease the impeller and fold the vanes in the direction of rotation |
| 7 | Fit the woodruff key, seat it fully, and check it is still there before closing |
| 8 | Torque the four bolts evenly, refill the gear oil, then run on muffs and check the tell tale |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | 3 year |
| Packaging | Sealed retail packaging |
Before You Buy
- Check the number on the old pump, 6BG-W0078-00 and 6BG-W0078-01 interchange
- Also written as 6BG-W0078-00-00 and 6BG W0078 00 00, crosses to Sierra 18-3490
- Fits Yamaha four stroke F30 and F40, three cylinder models
- The kit includes the impeller, cup, wear plate, cover, seal, gasket, key and bolts
- Two and four stroke pumps are not interchangeable, check your model first
- Refill the gear oil after the job and check it again after the first run
- 30-Day Easy Returns
- Ships from our warehouse with tracking
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Boat Owners' Review
Before You Buy
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