Timing Belt – Fits Yamaha Mercury 75HP 80HP 90HP 100HP 115HP 4-Stroke (Replaces 67F-46241-00, 804145)

Product Details

This Timing Belt is engineered as a direct-fit replacement for Yamaha 75–115 HP and Mercury 75–115 HP 4-stroke outboard engines spanning model years 1999–2011. Compatible with a wide range of F75, F80, F90, F100, and F115 series engines, this belt ensures reliable camshaft synchronization and precise valve timing in your 4-stroke powerhead.

This part directly replaces OEM part numbers 67F-46241-00 (Yamaha) and 804145 (Mercury), as well as cross-reference 67F-46241-00-00.

• Drop-in replacement for select Yamaha and Mercury 4-stroke outboards
• Designed for long-term durability under marine operating conditions
• Essential maintenance component for preventing valve-train failure

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

Part Type

Timing Belt

OEM Part Number

67F-46241-00 (Yamaha), 804145 (Mercury)

Cross Reference

67F-46241-00-00

Compatible Brands

Yamaha, Mercury

Engine Type

4-Stroke Outboard

Horsepower Range

75–115 HP

Model Years

1999–2017 (varies by model)

What's in the Box

• 1 × Timing Belt

Installation Notes

1. Disconnect the battery and remove engine cowling to access the timing cover.
2. Rotate the crankshaft to align timing marks on the camshaft and crankshaft gears to TDC (top dead center).
3. Remove the timing cover fasteners and carefully lift the cover away from the engine block.
4. Release tension on the timing belt tensioner and slide the old belt off the pulleys.
5. Inspect all pulleys, tensioner, and idler wheels for wear or damage; replace if necessary.
6. Route the new timing belt around the crankshaft sprocket, camshaft sprocket(s), and tensioner following the correct direction of rotation.
7. Ensure the timing marks remain aligned throughout installation.
8. Apply proper tension to the belt using the tensioner mechanism per manufacturer specifications.
9. Manually rotate the crankshaft two full revolutions and recheck all timing marks for accuracy.
10. Reinstall the timing cover with a new gasket or sealant as required.
11. Replace the engine cowling and reconnect the battery.
12. Start the engine and listen for unusual noise; confirm smooth operation before returning to service.

Troubleshooting & FAQ

How do I know if my timing belt needs replacement?

Common signs include rough idling, misfires, difficulty starting, loss of power, or visible cracking and fraying on the belt itself. Most manufacturers recommend replacement every 300–500 operating hours or per the service schedule in your owner's manual.

Will this belt fit my Mercury 100 HP 4-stroke?

Yes, this timing belt is compatible with Mercury 75–115 HP 4-stroke outboards. Cross-check your engine serial number or parts diagram to confirm fitment before ordering.

Can I install this belt without special tools?

While basic hand tools can remove and install the belt, a timing-mark alignment tool and torque wrench are strongly recommended to ensure proper tension and timing accuracy. Incorrect installation can lead to valve-train damage.

What happens if the timing belt breaks while running?

A broken timing belt will cause immediate loss of synchronization between the crankshaft and camshaft, potentially resulting in valve-to-piston contact and severe engine damage. Replace the belt at recommended intervals to avoid catastrophic failure.

Should I replace the tensioner and pulleys at the same time?

It is good practice to inspect the tensioner, idler pulleys, and water pump during belt replacement. If any component shows wear, replace it to avoid premature belt failure.

Is this belt pre-tensioned or do I need to adjust it?

This belt requires manual tensioning using the engine's built-in tensioner mechanism. Follow your service manual for the correct tension specification and adjustment procedure.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 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 against 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.