Alternator V-Belt for Yanmar 4JH4 Series (129671-42280E)
Alternator V-Belt for Yanmar 4JH4 Series (129671-42280E) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Alternator V-Belt for Yanmar 4JH4 Series (129671-42280E)
Product Details
This replacement Alternator V-Belt – Fits Yanmar 4JH4 Series Marine Diesel Engines (Replaces 129671-42280E, 129671-42280) is designed for 4JH4 series engines (75–110 HP) manufactured since 2006. It ensures reliable power transmission from the crankshaft pulley to the alternator, maintaining your vessel's charging system.
It is a direct replacement for Yanmar part numbers 129671-42280E and 129671-42280, and interchanges with Mitsuboshi RECMF-6455.
- Installation is specific to your engine model and may require loosening the alternator for proper tensioning.
- Engineered specifically for use in marine diesel engine environments.
- Includes one high-durability V-belt.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yanmar | 129671-42280E | OEM Reference |
| Yanmar | 129671-42280 | Superseded OEM Reference |
| Mitsuboshi | RECMF-6455 | Aftermarket Interchange |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This belt is confirmed to fit the following Yanmar marine diesel engines. Pay close attention to any serial number restrictions noted.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yanmar | 4JH4-E | 75 | 4-Stroke | Up to serial number E24939 | 129671-42280E | |
| Yanmar | 4JH4-TE | 75 | 4-Stroke | 07/2006 up to serial number E15601 | 129671-42280E | |
| Yanmar | 4JH4-HTE | 110 | 4-Stroke | All applicable | 129671-42280E | |
| Yanmar | 4JH4-HTE1 | 110 | 4-Stroke | All applicable | 129671-42280E |
Technical Specs
- Product Type
- Alternator V-Belt
- Installation
- Engine-specific
- Belt Type
- V-Belt
- Application
- Marine diesel engines
- Compatible Brands
- Yanmar (OEM) and compatible aftermarket options
- Warranty
- Varies by supplier: 6-month (OEM), 1-year (JLM Marine)
- Other Technical Attributes
- Mitsuboshi RECMF-6455 marking on belt
What’s in the Box
- 1 x Alternator V-Belt (Replaces 129671-42280E, 129671-42280)
Installation Notes
- Disconnect the battery terminals to prevent accidental starts.
- Locate the alternator and loosen its mounting and tensioning bolts.
- Carefully slide the old V-belt off the alternator and crankshaft pulleys.
- Inspect the pulleys for any wear, damage, or misalignment. Clean any debris from the grooves.
- Install the new belt onto the pulleys, ensuring it is seated correctly in the grooves.
- Apply tension to the belt according to your engine’s service manual specifications (typically about 1/2 inch of deflection under firm thumb pressure).
- Tighten the alternator's tensioning and mounting bolts securely.
- Reconnect the battery terminals and start the engine to check for proper operation and listen for any unusual noises.
Troubleshooting & FAQ
How do I know if this V-belt fits my specific engine?
This belt is for Yanmar 4JH4 series engines. The best way to confirm is to check the part number on your existing belt or in your engine's service manual. Cross-reference it with the part numbers listed here: 129671-42280E, 129671-42280, or Mitsuboshi RECMF-6455. Also, check the compatibility table for your specific engine model and serial number range.
What are common signs of a failing alternator belt?
Symptoms include visible cracks, fraying, or glazing on the belt surface. You may also hear a loud squealing noise from the engine, especially on startup or when under load. A flickering battery light or low voltage reading on your instruments can also indicate a slipping or broken belt.
What is the recommended replacement interval for a V-belt?
A specific interval depends on engine hours and operating conditions. As a general rule, inspect the belt during every routine service and plan to replace it every few hundred hours or every 2-3 years, or immediately if any signs of wear or damage are visible.
Is this belt identical to the original Yanmar OEM part?
This is a high-quality aftermarket part built to meet or exceed OEM specifications. While it performs the same function and fits the same models, it is not an original Yanmar-branded part. It offers comparable performance and durability at a better value.
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 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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