Timing Belt – Fits Tohatsu, Mercury, Yamaha 9.9-20 HP (Replaces 3H8-10061-0, 57-835392Q, 66M-46241-00-00)
Timing Belt – Fits Tohatsu, Mercury, Yamaha 9.9-20 HP (Replaces 3H8-10061-0, 57-835392Q, 66M-46241-00-00) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
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Timing Belt – Fits Tohatsu, Mercury, Yamaha 9.9-20 HP (Replaces 3H8...
Timing Belt – Fits Tohatsu, Mercury, Yamaha 9.9-20 HP (Replaces 3H8-10061-0, 57-835392Q, 66M-46241-00-00) is backordered and will ship as soon as it is back in stock.
Product Details
This high-quality engine Timing Belt – Fits Tohatsu, Mercury, Yamaha 9.9-20HP 4-Stroke Outboards is designed for reliable performance in a range of 4-stroke marine engines. It is engineered to fit specific Tohatsu/Nissan 9.9-20HP (2002–2014), Mercury/Mariner 8-15HP (up to 2008), and Yamaha F9.9-F15 (1998–2005) models, ensuring precise valve timing and engine synchronization.
This belt serves as a direct interchange for Tohatsu 3H8-10061-0/3H8100610M, Mercury 57-835392Q/835392/835392Q, Sierra 18-15147, and Yamaha 66M-46241-00-00/F15-07000002.
- Method: Direct-fit replacement for internal engine component.
- Material: Durable synthetic rubber with reinforcement fibers for longevity.
- Included: One engine timing belt.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Tohatsu | 3H8-10061-0 |
| Tohatsu | 3H8100610M |
| Mercury | 57-835392Q |
| Mercury | 835392 |
| Mercury | 835392Q |
| Sierra | 18-15147 |
| Yamaha | 66M-46241-00-00 |
| Yamaha | F15-07000002 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Tohatsu and Nissan engines, verify your model and year range falls within the compatibility list.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Tohatsu | MFS9.9A/B | 9.9 | 4-Stroke | 2002 | 3H8-10061-0 |
| Tohatsu | MFS9.9B2/C | 9.9 | 4-Stroke | 2003–2011 | 3H8-10061-0 |
| Tohatsu | MFS15A/B | 15 | 4-Stroke | 2002 | 3H8-10061-0 |
| Tohatsu | MFS15B2/C | 15 | 4-Stroke | 2003–2014 | 3H8-10061-0 |
| Tohatsu | MFS18B/B2 | 18 | 4-Stroke | 2002–2008 | 3H8-10061-0 |
| Tohatsu | MFS20C | 20 | 4-Stroke | 2008–2014 | 3H8-10061-0 |
| Nissan | NSF9.9A/B | 9.9 | 4-Stroke | 2002 | 3H8-10061-0 |
| Nissan | NSF9.9B2/C | 9.9 | 4-Stroke | 2003–2008 | 3H8-10061-0 |
| Nissan | NSF15A/B | 15 | 4-Stroke | 2002 | 3H8-10061-0 |
| Nissan | NSF15B2/C | 15 | 4-Stroke | 2003–2008 | 3H8-10061-0 |
| Nissan | NSF18B/B2 | 18 | 4-Stroke | 2002–2008 | 3H8-10061-0 |
| Nissan | NSF20C | 20 | 4-Stroke | 2008–2009 | 3H8-10061-0 |
For Mercury and Mariner engines, fitment is determined by serial number. Check your engine's serial number against the ranges provided.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | Outboard | 8 | 4-Stroke | 0P086824-0P400999 | 57-835392Q | Serial number range |
| Mercury | Outboard | 9.9 | 4-Stroke | 0P075166-0P400999 | 57-835392Q | Serial number range |
| Mercury | Outboard | 9.9 | 4-Stroke | 0G760300-1B226999 | 57-835392Q | Serial number range |
| Mercury | Outboard | 13.5 | 4-Stroke | 0P134638-0P400999 | 57-835392Q | Serial number range |
| Mercury | Outboard | 13.5 | 4-Stroke | 0P401000 & Up | 57-835392Q | Serial number range |
| Mercury | Outboard | 15 | 4-Stroke | 0P075166-0P400999 | 57-835392Q | Serial number range |
| Mercury | Outboard | 15 | 4-Stroke | 0G760300-1B226999 | 57-835392Q | Serial number range |
| Mercury | Outboard | 15 | 4-Stroke | 0P401000 & Up | 57-835392Q | Serial number range |
| Mercury | Outboard | 15 | 4-Stroke | 1B227000-1B727495 | 57-835392Q | Serial number range |
| Mariner | Outboard | 9.9 | 4-Stroke | 1995–1996 | 57-835392Q | Various serial numbers |
For Yamaha engines, confirm your model and production year range.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F9.9-2 | 9.9 | 4-Stroke | 1998–2005 | 66M-46241-00-00 | |
| Yamaha | T9.9-2 | 9.9 | 4-Stroke | 2005–2006 | 66M-46241-00-00 | Up to April 2006 |
| Yamaha | F15 | 15 | 4-Stroke | 1998–2005 | 66M-46241-00-00 | Up to April 2005 |
Technical Specs
- Product Type
- Engine Timing Belt
- Installation
- Direct replacement
- Fuel Type
- Gasoline
- Connection
- Internal engine component
- Housing Material
- Synthetic rubber with reinforcement fibers
- Warranty
- Varies by manufacturer (typically 1 year against manufacturing defects)
What’s in the Box
- 1 x Timing Belt (3H8-10061-0 / 66M-46241-00-00 / 57-835392Q)
Installation Notes
- Disconnect the battery and spark plug wires for safety.
- Remove the engine cowling and any interfering components to access the flywheel and timing belt cover.
- Carefully remove the flywheel using the appropriate puller tool. Do not strike the flywheel or crankshaft.
- Remove the timing belt cover to expose the belt and sprockets.
- Align the timing marks on the crankshaft and camshaft sprockets with the marks on the engine block.
- Loosen the tensioner, remove the old timing belt, and inspect the sprockets and tensioner for wear.
- Install the new belt, ensuring it is properly seated on the sprockets and that the timing marks remain aligned.
- Apply correct tension to the new belt as per the manufacturer's service manual.
- Reinstall the timing belt cover, flywheel, and all other components in reverse order of removal.
- Reconnect the spark plug wires and battery, then test the engine.
Troubleshooting & FAQ
How do I know if this timing belt fits my engine?
The most reliable method is to match your engine's model, year, and serial number to the compatibility tables above. Also, cross-reference the part number stamped on your old belt with the numbers in our Part Number Matrix.
What are the signs of a failing timing belt?
Common symptoms include a ticking noise from the engine, rough idling, misfires, or a complete failure to start. Visual inspection may reveal cracks, fraying, missing teeth, or excessive slack in the belt.
What is the recommended replacement interval?
Refer to your outboard engine's service manual for the manufacturer-recommended interval, which is typically based on operating hours or years (e.g., every 1000 hours or 5 years), whichever comes first. Proactive replacement is crucial to prevent catastrophic engine failure.
Can I replace the timing belt myself?
While possible for experienced mechanics, this job requires special tools (like a flywheel puller) and precise knowledge of aligning timing marks. Incorrect installation can cause severe engine damage. We strongly recommend professional installation.
Is this a complete kit?
This listing is for the timing belt only. Tensioners, idlers, or seals are not included unless specified in the "What's in the Box" section.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9001 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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