Sierra 3042 Yamaha Impeller
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The Sierra 3042 (18-3042) Impeller is a replacement lower-unit water pump impeller for compatible Yamaha 75–100 HP four-stroke outboards. Six flexible blades draw cooling water through the gearcase and circulate it through the engine. Replaces Yamaha OEM part number 67F-44352-00-00.
Parts Desk Insight — Best Use
Note that 47-3042 is the distributor SKU, not a Yamaha OEM-format number. When cross-referencing, match to Yamaha 67F-44352-00-00 and verify against the exact engine model and production year before opening the lower unit. Yamaha used different gearcase and water pump configurations within the same horsepower ranges, so HP alone is not a reliable selector.
Replace every 2–3 seasons or 200 hours regardless of visible wear. Impeller vanes harden and lose flexibility before showing obvious damage, reducing cooling flow without warning.
This impeller is included in Sierra water pump kits 18-3451 and 18-3409 for a complete pump service.
Key Specifications
- Sierra part number: 18-3042
- Six flexible impeller blades
- Fits compatible Yamaha F75, F80, F90, F100 four-stroke outboards
- Impeller only — housing, plate, key, and seals not included
- UPC: 808282256852
Engine Compatibility
Documented Yamaha applications:
- F75: 2003–2005
- F80: 1999–2003
- F80 Jet Drive: 2001–2002
- F90: 2003–2005
- F90 Jet Drive: 2003–2004
- F100: 1999–2002
Always verify by full engine model number, production year, shaft length, gearcase configuration, and OEM parts diagram showing Yamaha 67F-44352-00-00.
Alternate Part Numbers
- Sierra: 18-3042 / 118-3042
- Yamaha: 67F-44352-00-00 / 67F-44352-00
- Mallory Marine: 9-45612
Installation Notes
Lower-unit removal is required to access the water pump assembly. During service: inspect the pump housing, wear plate, key, cup, and seals; remove any broken impeller fragments from cooling passages; lubricate the new impeller with clean soapy water or approved assembly lubricant; rotate the driveshaft in its normal operating direction while seating the housing over the blades. Confirm strong cooling-water telltale flow before operating under load. Never operate the outboard without an adequate cooling-water supply.
Compatible Yamaha Water Pump Kits
- Sierra 3433 Yamaha Water Pump Repair Kit
- Sierra 3434 Yamaha Water Pump Repair Kit
- Sierra 3442 Yamaha Water Pump Repair Kit
- Sierra 3371 Yamaha Water Pump Repair Kit
- Sierra 3312 Yamaha Water Pump Repair Kit
- Sierra 33131 Yamaha Water Pump Repair Kit
Related Yamaha Impellers
Always confirm fitment against your Yamaha service manual and full model/year before ordering.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.