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Description
Water Pump Repair Kit – Fits Mercury 9.9–20 HP 4-Stroke Outboards (Replaces 8M0135821)Water Pump Repair Kit Fits Mercury 9. 920 HP 4 Stroke Outboards (Replaces 8M0135821) This water pump repair kit is designed for Mercury 4 Stroke 9. 920 HP outboard engines with serial numbers 0R833820 and above, including ProKicker and SeaPro models. It provides a direct replacement solution built to meet or exceed original equipment manufacturer specifications. Replaces the following part numbers: Mercury Quicksilver 8M0135821, 98 8M0135821, Mercury
Water Pump Repair Kit – Fits Mercury 9.9–20 HP 4-Stroke Outboards (Replaces 8M0135821)
This water pump repair kit is designed for Mercury 4-Stroke 9.9–20 HP outboard engines with serial numbers 0R833820 and above, including ProKicker and SeaPro models. It provides a direct replacement solution built to meet or exceed original equipment manufacturer specifications.
Replaces the following part numbers: Mercury/Quicksilver 8M0135821, 98-8M0135821, Mercury 8M0137849, and Tohatsu 3RS-87322-1.
- Engineered for a direct fit to the lower unit for straightforward installation.
- Produced to meet Mercury Marine original equipment manufacturer specifications for reliable performance.
- Complete kit includes the essential components for a water pump service: impeller, upper/lower housings, and plate.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury / Quicksilver | 8M0135821 |
| Mercury / Quicksilver | 98-8M0135821 |
| Mercury | 8M0137849 |
| Tohatsu | 3RS-87322-1 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 4-Stroke Outboards | 9.9 | 4-Stroke | Serial numbers 0R833820 and above | 8M0135821 | Includes ProKicker and SeaPro models |
| Mercury | 4-Stroke Outboards | 10 | 4-Stroke | Serial numbers 0R833820 and above | 8M0135821 | Includes ProKicker and SeaPro models |
| Mercury | 4-Stroke Outboards | 15 | 4-Stroke | Serial numbers 0R833820 and above | 8M0135821 | Includes ProKicker and SeaPro models |
| Mercury | 4-Stroke Outboards | 20 | 4-Stroke | Serial numbers 0R833820 and above | 8M0135821 | Includes ProKicker and SeaPro models |
| Mercury | 2-Cylinder (333cc) | 9.9-20 | 4-Stroke | - | 8M0135821 | For 2-Cylinder 333cc engines |
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Tohatsu | MFS | 15 | 4-Stroke | 3RS-87322-1 | Cross-reference to Mercury 8M0135821 |
| Tohatsu | MFS | 20 | 4-Stroke | 3RS-87322-1 | Cross-reference to Mercury 8M0135821 |
Technical Specifications
| Specification | Value |
|---|---|
| Product Type | Water Pump Repair Kit |
| Installation | Direct replacement, requires common shop tools |
| Connection | Direct fit to lower unit |
| Dimensions | Weight: 0.63 lb (0.29 kg) Length: 4.25 in (108 mm) Width: 4.50 in (114 mm) Height: 6.25 in (159 mm) |
| Weight | 0.29 kg (0.63 lb) |
| Other Technical Attributes | Produced to meet Mercury Marine original equipment manufacturer specifications |
Package Contents
- 1 x Water Pump Repair Kit Assembly (Replaces 8M0135821)
- 1 x Water Pump Impeller
- 1 x Upper Housing
- 1 x Lower Housing
- 1 x Plate
Installation Guide
- Disconnect the battery and shift the outboard into neutral.
- Remove the propeller and drain the gearcase oil.
- Unbolt and carefully lower the gearcase from the drive shaft housing.
- Remove the old water pump housing bolts and lift the housing assembly off.
- Clean the mounting surfaces and inspect the driveshaft for any wear or damage.
- Install the new gaskets, plate, and impeller, ensuring the keyway is aligned.
- Lubricate the inside of the new housing and impeller with grease.
- Install the new housing, ensuring the impeller vanes are turned in the correct direction (clockwise).
- Tighten the housing bolts to the manufacturer's specified torque.
- Re-install the gearcase, making sure the water tube and shift shaft align correctly.
- Refill the gearcase with fresh oil and re-install the propeller.
- Reconnect the battery and test the engine in the water, verifying water is exiting the tell-tale port.
Troubleshooting & FAQ
Q: How do I confirm this kit fits my Mercury outboard?
A: This kit is designed for Mercury 4-Stroke 9.9–20 HP outboards with serial numbers 0R833820 and higher. Please use our Mercury Serial Number Guide to verify your engine's serial number before ordering.
Q: What are the signs of a failing water pump?
A: Common signs include a weak or non-existent water stream from the "tell-tale" outlet, engine overheating alarms, or a melted/deformed pump housing upon inspection.
Q: How often should the water pump impeller be replaced?
A: For preventative maintenance, it is recommended to inspect the water pump impeller annually and replace it every 1-2 years or every 100-200 hours of use, depending on operating conditions (e.g., saltwater vs. freshwater).
Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
- Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
- Fast Global Shipping: Free delivery worldwide in 5–15 days.
- Direct from Manufacturer: Competitive pricing without compromising quality.
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy