Timing Belt for Yamaha F6A F6B F8C F8F FT8D FT8G F9.9F FT9.9J FT9.9G FT9.9L | JLM Marine
This replacement timing belt is engineered for reliable performance across Yamaha's compact 4-stroke outboard lineup, covering F6, F8, FT8, and F9.9 series engines. Designed to meet OEM specifications, this belt ensures precise camshaft timing and smooth engine operation in demanding marine environments.
This part directly replaces Yamaha OEM 68T-46241-00 and Sierra 18-15138, providing an exact-fit aftermarket solution for routine maintenance or emergency replacements.
- Critical timing component for 4-stroke Yamaha outboards
- Compatible with F6, F8, FT8, and F9.9 model families
- Direct OEM cross-reference for easy identification
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Yamaha |
68T-46241-00 |
| Sierra |
18-15138 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Yamaha owners, here's a guide to help you identify your engine's serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.
| Brand |
Model |
| Yamaha |
F6A |
| Yamaha |
F6B |
| Yamaha |
F8C |
| Yamaha |
F8F |
| Yamaha |
FT8D |
| Yamaha |
FT8G |
| Yamaha |
F9.9F |
| Yamaha |
FT9.9J |
| Yamaha |
FT9.9G |
| Yamaha |
FT9.9L |
Technical Specifications
| Specification |
Value |
| OEM Part Number |
68T-46241-00 |
| Aftermarket Reference |
Sierra 18-15138 |
| Application |
Timing Belt |
| Engine Type |
4-Stroke Outboard |
Package Contents
- 1 × Timing Belt (68T-46241-00)
Installation Guide
-
Safety first: Disconnect the battery and ensure the engine is completely cool before beginning work.
-
Access the timing cover: Remove the engine cowling and any components obstructing access to the timing belt cover.
-
Remove the timing cover: Unbolt and carefully remove the timing cover to expose the timing belt and pulleys.
-
Mark timing positions: Before removing the old belt, mark the camshaft and crankshaft alignment positions using paint or a marker.
-
Release belt tension: Loosen the tensioner bolt to release tension on the old timing belt.
-
Remove the old belt: Carefully slide the worn timing belt off the camshaft and crankshaft pulleys.
-
Inspect components: Check pulleys, tensioner, and idler for wear or damage; replace if necessary.
-
Install the new belt: Route the new timing belt around the crankshaft pulley first, then over the camshaft pulley, ensuring correct rotational direction.
-
Align timing marks: Verify that all timing marks on the camshaft and crankshaft align precisely with your reference marks.
-
Apply proper tension: Adjust the tensioner according to manufacturer specifications and tighten the tensioner bolt securely.
-
Reinstall the timing cover: Replace the timing cover, engine components, and cowling, ensuring all fasteners are torqued correctly.
-
Test operation: Reconnect the battery and run the engine at idle to confirm smooth operation and proper timing.
Troubleshooting & FAQ
Q: How do I confirm this timing belt fits my Yamaha outboard?
A: Cross-reference your engine model with the compatibility table above (F6A, F6B, F8C, F8F, FT8D, FT8G, F9.9F, FT9.9J, FT9.9G, FT9.9L). Verify your OEM part number is 68T-46241-00 by checking your service manual or using the Yamaha parts diagrams linked above.
Q: How often should I replace the timing belt on my Yamaha outboard?
A: Yamaha typically recommends timing belt inspection and replacement based on operating hours or calendar time (consult your owner's manual for exact intervals). Most manufacturers suggest replacement every 3-5 years or 300-500 hours of operation, whichever comes first.
Q: What happens if the timing belt fails?
A: A failed timing belt can cause catastrophic engine damage, including bent valves and piston damage. Regular inspection and timely replacement are critical for engine longevity.
Q: Can I install this timing belt myself?
A: Installation requires mechanical experience and proper tools. If you're not comfortable with internal engine work, consult a certified marine technician to ensure correct timing alignment and tension.