Sierra Yamaha Water Pump Repair Kit 18-3442 | F115 / LF115
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Sierra Yamaha Water Pump Repair Kit 18-3442
- Part Number: 18-3442 (Sierra)
- Brand: Sierra
- Product Type: Water Pump Repair Kit (housing not included)
- Fits: Yamaha F115 / LF115 4-stroke outboards
- UPC: 808282291679
Sierra 18-3442 is a water-pump repair kit for selected Yamaha F115 and LF115 4-stroke outboards. It supplies the primary internal wear components needed to rebuild the lower-unit water pump while reusing the existing pump housing — provided that housing is still smooth and undamaged. The kit cross-references to Yamaha OEM kit numbers 68V-W0078-00-00 and 68V-W0078-01-00.
Kit Contents
- Water pump impeller
- Impeller key
- Wear plate
- Insert cup
- Water pump gasket
- O-rings
- Mounting bolts and washers
- Dowel / locating pin
Note: The main water pump housing is not included. If the existing housing is scored, melted, or distorted, a complete pump kit is required.
Compatible Applications
Verified Yamaha 4-stroke outboard applications:
- Yamaha F115 — 115 HP, 4-stroke, 2002 and newer
- Yamaha LF115 — 115 HP, 4-stroke
Always confirm engine model, model year, and serial number before ordering. Yamaha revised the 68V-W0078 kit family over time — matching the existing OEM pump-kit number from your engine's parts diagram is the most reliable fitment method.
Cross-Reference Part Numbers
- Sierra: 18-3442
- Supplier/Catalogue Reference: 47-3442
- Yamaha: 68V-W0078-00-00
- Yamaha: 68V-W0078-01-00
- Quicksilver: 8M6012804
- Mallory: 9-48611
When to Service the Water Pump
- Cooling water discharge weakens or becomes intermittent
- Engine temperature rises abnormally
- Impeller is cracked, stiff, or permanently set
- Pump has ingested sand, silt, or debris
- Gasket or O-rings show leakage or deterioration
- Lower unit is already removed for scheduled cooling system maintenance
Installation Notes
- Remove the lower unit following Yamaha service procedures for the F115 / LF115
- Inspect the existing pump housing carefully for grooves, distortion, or heat damage before reusing it
- Replace the impeller, wear plate, insert cup, O-rings, gasket, and all supplied hardware as a complete set
- Lightly lubricate the impeller with a water-safe assembly lubricant before fitting
- Rotate the driveshaft in its normal operating direction while lowering the pump housing over the impeller
- Confirm all impeller vanes fold in the correct rotational direction
- Verify correct water-tube engagement during gearcase reinstallation
- Check cooling-water discharge after startup before returning to service
Parts Desk Insights
Best use case: This kit is the right choice for scheduled water pump service on Yamaha F115 and LF115 outboards where the pump housing is in good condition. It covers all the internal wear parts in one package and is the direct OEM replacement for engines specifying 68V-W0078-00-00 or 68V-W0078-01-00. It's also the logical choice any time the lower unit is already off for other scheduled service.
Common issue: The most frequent ordering mistake is selecting this kit when the pump housing also needs replacement. If the housing shows scoring, warping, or heat discoloration, this repair kit alone will not restore proper cooling performance — a complete pump kit including the housing is needed instead. Always inspect the housing before ordering. Also note that Yamaha revised this kit series over time, so confirming the OEM number rather than selecting by model year alone is the safest approach.
Browse all water pump service kits in our Impeller Service Kits collection, or shop Engine Parts & Maintenance for related cooling system components.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 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.