Best 115 4 Stroke Outboard Parts and Kits for Reliable Performance
Answering the question “which parts are best for a 115 4-stroke outboard?” this guide highlights top oil change kits, water pump impeller kits, and oil filters suited for Mercury and Yamaha/Mercury-compatible models around 75–115 HP. The selections emphasize long-term protection, ease of maintenance, and compatibility for common 115 HP EFI four-stroke engines. The buyer types best served include boat owners performing routine maintenance, DIY enthusiasts, and those upgrading stock components for improved reliability on saltwater or freshwater trips.
| Product | Best For | Why Picked |
|---|---|---|
| Mercury 8M0107510 Oil Change Kit | Mercury 75–115hp EFI Outboards | All-in-one kit with oil, filter, drain hose, and additive package. |
| Quicksilver 10W-30 Oil Change Kit | Mercury 70–115hp 2.1L Outboards | Comprehensive kit with premium oil and filter for long-term lubrication. |
| GHmarine Water Pump Impeller Kit | Yamaha 75–115 HP 4-Stroke | Includes impeller and housing for reliable cooling system maintenance. |
| Mercury 8M0081917 25W-40 Change Kit | Mercury 75–115hp EFI | Alternative oil viscosity option with filter and seals. |
| Quicksilver 8M0162830 Oil Filter | Mercury/Mariner 4-Stroke 25–115hp | High-quality filtration with anti-drain back for quick starts. |
Mercury 8M0107510 10W-30 4-Stroke Oil Change Kit
Includes five 1-liter Mercury 10W-30 4-Stroke Marine Engine Oil bottles, an oil filter, drain hose, and instructions. The marine-specific additive package adds corrosion inhibitors to protect engines on the water and during storage. This kit is best for Mercury 2.1L, 75–115hp EFI engines with serial numbers starting from 2B094996. Choose this for a complete, brand-aligned oil service that minimizes guesswork.
Best for: Mercury EFI 75–115hp owners who want a ready-to-use kit with all essential components, including corrosion inhibitors for frequent launches.
Limitations: Requires adherence to Mercury-specific oil specification; not universal for non-Mercury brands.
Quicksilver 10W-30 Oil Change Kit for 4-Stroke 75–115hp Mercury
Contains five 1L bottles of Quicksilver 10W-30 4-Stroke Marine Engine Oil, a premium Quicksilver oil filter, and a drain hose. Formulated with corrosion inhibitors and lubricity to reduce wear, this kit supports reliable heat management and smoother starts. Best for: Mercury 70–115hp 2.1L outboards that require a compatible oil blend from the same brand family.
Limitation: Some users may prefer a Mercury-branded filtration component for brand consistency, though cross-compatibility is common in many 4-stroke outboards.
GHmarine 68VW0078 Water Pump Impeller Kit for Yamaha 4-Stroke
This kit is designed for Yamaha 75–115 HP 4-Stroke outboards and replaces multiple OEM part numbers, including 61A-44311-01-00 and 68V-W0078 variants. The kit helps maintain proper cooling by ensuring reliable impeller operation, guarding against overheating. Best for: Yamaha-branded four-stroke owners or those seeking a compatible impeller replacement with housing.
Caution: Verify model compatibility to ensure correct pump housing fit and gunmetal impeller type for your engine year.
Mercury 8M0081917 25W-40 4-Stroke Oil Change Kit
Designed for Mercury 1.7L, 75–115hp EFI four-stroke outboards with serial ranges 1B366823–2B094995. It includes five 1L bottles of Mercury 25W-40 4-Stroke Engine Oil, a filter, drain plug seal, and instructions. The marine-grade additives provide corrosion protection for water and storage.
Best for: Mercury 75–115hp owners seeking a higher-viscosity option (25W-40) when operating in warmer conditions or when oil push-forces require thicker lubrication.
Limitation: Not compatible with smaller 1.7L engines outside the specified serial range.
Quicksilver 8M0162830 Oil Filter for Mercury/Mariner 4-Stroke
Engineered for Mercury and Mariner 4-Stroke outboards between 25–115hp, this filter supports cleaner oil and long-lasting lubrication by preventing contaminants from entering the engine. It features an anti-drain back valve to aid start-up lubrication and reduce dry starts. Best for: Mercury/Mariner four-stroke engines requiring reliable oil filtration.
Limitation: Filter availability can vary by model year; verify compatibility with your exact Mercury/Mariner serial and HP rating before purchasing.
UanofCn 68VW0078 Water Pump Impeller Kit
This Yamaha-focused impeller kit covers 50–115 HP models, offering a housing-inclusive replacement to maintain cooling efficiency. It targets multiple Yamaha 4-Stroke configurations and shares compatibility with several brand housings.
Choose this if you need a comprehensive impeller housing replacement for a Yamaha-equipped 115 HP outboard, but ensure the exact model year and housing type match.
Fanthorn 4-Stroke Transom Saver
Transom savers reduce engine weight stress on the transom and stabilize the motor during transport. This stainless steel-frame tote is designed to fit a range of 75–300 HP engines, helping prevent damage from vibrations and movement. Best for: Owners who frequently trailered boats or store engines with the motor lifted.
Limitation: Not a maintenance part; it’s a transport accessory rather than part of routine engine lubrication or cooling maintenance.
Buying Guide: Key Purchase Considerations
- Engine compatibility: Confirm HP and model year for Mercury, Quicksilver, Yamaha, or Mariner four-stroke 115 HP class to ensure fluids and filters match specifications.
- Oil viscosity: 10W-30 is common for many 4-stroke marine engines; 25W-40 offers higher protection in warmer environments or older engines with specific tolerances.
- Filtration and filtration materials: Anti-drain back valves help with cold starts; choose filters designed for marine use to resist fuel/sea conditions.
- Cooling system components: Impeller kits with housing support reliable water flow; improper impellers can lead to overheating and reduced performance.
- Maintenance kit completeness: Some kits include hoses, seals, and additive packages—these matter for thorough servicing and corrosion protection.
- Brand compatibility vs. cross-brand use: Some brands offer cross-brand compatibility; confirm with your engine’s serial numbers and OEM part numbers.
- Budget vs. long-term savings: Investing in comprehensive kits reduces on-water downtime and repeated purchases of mismatched parts.
Frequently Asked Questions
- What is the best oil for a 115 HP four-stroke outboard?
Answer: Many 115 HP four-stroke engines perform well with 10W-30 oils; some situations may benefit from 25W-40. Check your engine’s manual for exact specification. - Do I need a brand-specific oil kit?
Answer: Brand-specific kits simplify compatibility and warranty expectations, but cross-brand oil blends are common among manufacturers. Always verify with your model and serial number. - Can I replace a water pump impeller without an entire kit?
Answer: If you only need the impeller, you can source the impeller and housing separately; however, a kit ensures you have a complete cooling system replacement if other parts fail. - How often should I replace the oil in a 115 HP four-stroke?
Answer: Oil change intervals vary by usage; follow the engine’s manual, especially after long storage, saltwater use, or high-performance runs. - Is an anti-drain back valve important in an oil filter?
Answer: Yes, it helps with immediate lubrication on startup and reduces dry starts, particularly after extended storage. - Are transom savers necessary for trailering?
Answer: They reduce transom stress and engine movement during transport, protecting the boat and engine mounting.