Mercury Quicksilver 300-Hour Service Kit 8M0090559 – 40–60 HP FourStroke EFI Command Thrust
No restocking fees on eligible returns
You have 30 days to request a return. All sale items are final sale.
Customer pays return postage. Return postage is reimbursed if we made a mistake.
Mercury Quicksilver 300-Hour Service Kit — 40–60 HP FourStroke EFI Command Thrust
Part Number: 8M0090559 | GTIN: 745061933668
Brand: Mercury / Quicksilver | Service Interval: 300 hours or 3 years (whichever comes first)
Genuine Mercury Quicksilver OEM 300-hour scheduled maintenance kit for 4-cylinder 40–60 HP FourStroke EFI outboards equipped with BigFoot or Command Thrust gearcases, serial number 1C000001 and higher. All major service components in one package.
Compatible Applications
- Mercury 40 HP FourStroke EFI — BigFoot / Command Thrust gearcase, S/N 1C000001+
- Mercury 50 HP FourStroke EFI — BigFoot / Command Thrust gearcase, S/N 1C000001+
- Mercury 60 HP FourStroke EFI — BigFoot / Command Thrust gearcase, S/N 1C000001+
Confirm engine horsepower, gearcase configuration, and serial number before ordering. Standard (non-BigFoot / non-Command Thrust) versions of otherwise similar engines may require a different service kit.
Kit Contents
- Engine oil filter
- Low-pressure fuel filter
- High-pressure fuel filter
- Oil-drain seal
- Gearcase drain seals
- Thermostat
- Thermostat gaskets
- Spark plugs (set of 4)
- Water-pump impeller repair kit
- Power-trim anode
- Lower-unit anode
Verify exact contents on the kit label — components may vary by production date.
Service Interval
Perform 300-hour service every 300 hours of operation or every 3 years, whichever occurs first. Always follow the applicable Mercury outboard service manual for complete procedures. Engine oil and gear lubricant are sold separately.
Installation Notes
Follow Mercury service procedures for the exact engine serial number. Inspect the water-pump housing, thermostat housing, fuel system, spark plug condition, gearcase drain plugs, and anode mounting surfaces during service.
Related Products
- Mercury 40–60 HP FourStroke EFI 100-Hour Maintenance Kit — 8M0232733
- Mercury Fuel Filter Kit – 40/50/60 HP EFI FourStroke | 8M0149607
- Mercury Quicksilver Fuel Filter Assembly 879884T – 20 Micron | EFI FourStroke 30–60 HP
- Mercury Quicksilver Inline Fuel Filter 879885K | EFI FourStroke & Verado
- Mercury Quicksilver 300-Hour Service Kit 8M0149930 — 3.4L V6 FourStroke
Alternate Part Numbers
- Mercury / Quicksilver OEM: 8M0090559
- GTIN: 745061933668
Parts Desk Insights
The critical fitment detail for 8M0090559 is the BigFoot / Command Thrust gearcase — the larger lower unit commonly found on jon boats, aluminum fishing boats, and heavy-displacement tenders. Horsepower alone is not enough to confirm fitment. If a customer is unsure whether they have Command Thrust, have them check the engine cowl label or cross-reference via serial number. Customers with standard gearcase 40–60 HP EFI models should confirm the correct kit for their configuration using the Mercury parts catalog.
Shipping information
Free standard shipping in Canada on eligible orders over $150 CAD after discounts and before taxes, up to 15 kg. Freight, oversized, remote-area and express exclusions apply. See our shipping policy.
In-stock at Marisol: usually ready for pickup the same day. Supplier-stock items: usually ready for pickup within 24 hours. Wait for your pickup-ready confirmation.
In-stock items receive priority shipping processing. Supplier-stock items generally ship within 1–3 business days. Special-order timing varies. Carrier delivery time is additional.
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.
No restocking fee applies to eligible returns. Customers arrange and pay return postage unless we made a mistake, in which case we reimburse return postage. See the return policy for eligibility and exclusions, or contact us.