Water Pump Impeller Kit 646-44352-01 646-44352-00 18-3072 47-80395M for Yamaha 2A 2B Mariner 2 HP Two Stroke with Drive Pins — United Kingdom Local Warehouse
Water Pump Impeller Kit 646-44352-01 646-44352-00 18-3072 47-80395M for Yamaha 2A 2B Mariner 2 HP Two Stroke with Drive Pins — United Kingdom Local Warehouse
Product Overview
Water pump impeller kit part with 2 drive pins for Yamaha and Mariner 2 HP two stroke outboards, replacing 646-44352-01 and 646-44352-00 and crossing to Sierra 18-3072. The impeller measures 47.5 mm (1.87 in) outside, 10.88 mm (0.43 in) at the shaft and 13.85 mm (0.55 in) high, with 6 neoprene blades on a key drive. Shipped from our United Kingdom local warehouse.
On a 2 HP motor the impeller is driven by two small pins, and the pins wear before the rubber does. A flattened pin lets the impeller sit still while the shaft turns, so the motor overheats with a pump that looks perfect when you open it.
Fits the Yamaha 2A and 2B from 1984 to 2002 and the Yamaha built Mariner 2 HP of the same years. Anything 3 HP and above uses a different, larger pump, so measure before ordering.
Specifications
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Water pump impeller kit with drive pins |
| Outer Diameter | 47.5 mm (1.87 in) |
| Inner Diameter | 10.88 mm (0.43 in) |
| Height | 13.85 mm (0.55 in) |
| Blades | 6 |
| Shaft Type | Key drive |
| Material | Neoprene rubber |
| Net Weight | 25.5 g |
OEM Cross Reference
| Brand | Part Numbers |
|---|---|
| Yamaha | 646-44352-01, 646-44352-00 |
| Mercury Mariner | 47-80395M |
| Sierra | 18-3072 |
| Yamaha drive pin | 96304-09068 |
Compatible Engines
| Outboard | Model | Years | Serial Check |
|---|---|---|---|
| Yamaha 2 HP two stroke | 2A | 1984 to 2002 | Serial starts 646 |
| Yamaha 2 HP two stroke | 2B | 1984 to 2002 | Serial starts 6A1 |
| Mariner 2 HP two stroke | Yamaha built | 1984 to 2002 | Same impeller, Mariner cowling |
| Not for | 3 HP and above | Any year | Uses the larger 6E0 or 6L5 pump |
What's Included
| Component | Reference | Qty |
|---|---|---|
| Water pump impeller, 6 blade | 646-44352-01, 47.5 mm (1.87 in) | 1 |
| Drive pin | 96304-09068, 3.5 x 8.86 mm | 2 |
Drive Pins: The Part That Fails First
| What You Find | What It Means | What To Do |
|---|---|---|
| Pins flattened on one side | Impeller slipping on the shaft, weak flow | Renew both pins with the impeller |
| Pin bent or half worn through | The motor has been run with a dry or blocked pump | Check the housing and cover plate too |
| Pins missing from the old pump | Someone fitted the impeller without them | They are in this kit, use both |
| Impeller looks fine but does not turn | Pin has sheared inside the shaft slot | Dig out the remains before fitting the new pin |
| Slot in the shaft worn oval | Pin rocks and wears out in weeks | Check the shaft, a worn slot needs a new shaft |
| Telltale weak at low revs only | Pin slipping under load before it fails completely | Renew pins at the first sign, not at the failure |
Winter Lay-Up and Frost
| UK Use | Effect on the Pump | What To Do |
|---|---|---|
| Motor stored on the boat over winter | Water freezes in the pump below 0 °C and splits the housing | Flush and drain, store leg down |
| Shed or garage storage at 5 °C | Rubber goes hard and the blades set in one position | Renew the impeller before the season |
| Tender left on a mooring | Rain and frost cycle the pump every week | Take the motor home, or drain it fully |
| Estuary and harbour use | Salt and silt pack the intake and score the blades | Flush in fresh water after every trip |
| Trailer sailed in winter | Pump never dries out between trips | Drain after each launch, check the blades |
| First start after the lay up | Dry blades tear on a dry housing | Run on muffs before the motor goes on the boat |
No Telltale at the Ramp
| What You See | Usual Cause | Check Before Buying Parts |
|---|---|---|
| No telltale at idle | Impeller or pin failed, or the intake is blocked | Clear the intake grille first |
| Weak telltale that improves with revs | Worn blades or a slipping pin | Take the pump apart, check both |
| Telltale fine on muffs, nothing in the water | Intake above the waterline on the transom | Lower the motor, then recheck |
| Steam from the telltale | Pump is moving too little water | Impeller, housing and cover plate |
| Motor hot after 5 minutes at low revs | Impeller set from the winter lay up | Renew the impeller and the 2 pins |
| Water in the gear oil | Pump seal or housing gasket failed | This kit does not include the seals |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Check the serial number starts with 646 or 6A1, the 3 HP motor takes a different impeller |
| 2 | Measure the old impeller at 47.5 mm (1.87 in) outside and 13.85 mm (0.55 in) high |
| 3 | Drop the lower unit and drain the pump before opening it |
| 4 | Check the old pins for flat spots, they wear before the rubber does |
| 5 | Clean the shaft slot of pin fragments before fitting anything new |
| 6 | Fold the blades in the direction of rotation and lubricate with glycerine only |
| 7 | Fit both drive pins, one each side of the shaft |
| 8 | Run on muffs and check the telltale at idle, then again in the water under load |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Sealed retail packaging |
Shipping from United Kingdom
| Destination | Warehouse | Note |
|---|---|---|
| United Kingdom | United Kingdom local warehouse | Domestic delivery, no import duty |
| Ireland | United Kingdom local warehouse | Short transit, customs may apply |
| Channel Islands, Isle of Man | United Kingdom local warehouse | Tracked shipping available |
Before You Buy
- Check the serial number starts with 646 or 6A1, the 3 HP motor takes a different impeller
- Measure the old impeller at 47.5 mm (1.87 in) outside and 13.85 mm (0.55 in) high
- Check the old drive pins for flat spots, that is the usual cause of a weak telltale
- Check the pump housing for scoring, a grooved housing wears new blades out in a season
- This is the impeller and 2 drive pins, the housing, cover plate and seals are not included
- Flush and drain the pump before winter, frost splits the housing below 0 °C
- 30-Day Easy Returns
- Ships from our United Kingdom local warehouse
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