25132-004600 V Belt for Yanmar 4JHL 4JH2 4JH3 6PHM 3JHLP | JLM Marine

V Belt for Yanmar 4JHL 4JH2 4JH3 6PHM 3JHLP Marine Engines

This V Belt is designed as a direct replacement for Yanmar marine inboard engines, providing reliable performance for a wide range of models including the 4JHL, 4JH2, 4JH3, 6PHM, and 3JHLP series. Engineered to meet OEM specifications, this belt ensures proper tension and power transmission for your engine's alternator and other belt-driven components.

This part directly replaces Yanmar OEM part number 25132-004600, making it a cost-effective aftermarket solution for routine maintenance and replacement needs on your Yanmar marine diesel engine.

• Fits multiple Yanmar 4JH and 6PH series marine diesel engines
• Direct replacement for OEM part number 25132-004600
• Essential component for maintaining proper alternator and accessory drive function

Part Number Cross-Reference

Use this table to confirm the OEM part number for your Yanmar engine:

Compatible Engine Models

Confirm your engine model in the table below:

Package Contents

This package includes:

• 1 × V Belt

Installation Guide

1. Disconnect the negative battery cable to prevent accidental starting. Ensure the engine is cool before beginning work.
2. Locate the V belt on your Yanmar engine, typically running from the crankshaft pulley to the alternator. Take note of the belt routing path.
3. Release tension on the belt by loosening the alternator adjustment bolt and pivot bolt. Push the alternator toward the engine block to create slack.
4. Remove the old V belt from all pulleys, inspecting pulleys for wear, cracks, or damage while the belt is off.
5. Route the new V belt around all pulleys following the same path as the original. Ensure it seats properly in each pulley groove.
6. Pull the alternator away from the engine block to apply proper tension to the belt. The belt should deflect approximately 10-15mm (3/8"-5/8") when pressed midway between pulleys.
7. Tighten the alternator adjustment bolt to maintain tension, then secure the pivot bolt. Double-check belt tension after tightening.
8. Reconnect the negative battery cable and start the engine. Listen for any unusual squealing or slipping noises that may indicate improper tension or alignment.

Troubleshooting & FAQ

Q: How do I know if this V belt fits my Yanmar engine?
A: Check the compatible engine models table above to confirm your specific engine model is listed. Additionally, verify that your current belt matches OEM part number 25132-004600. If your model is listed but you notice any differences in size or configuration, contact us before purchasing.

Q: How often should I replace the V belt on my Yanmar marine engine?
A: Yanmar typically recommends inspecting the V belt every 250 operating hours and replacing it every 500-1000 hours or every 2-3 years, whichever comes first. Replace immediately if you notice cracking, glazing, fraying, or unusual noise during operation.

Q: What are the signs that my V belt needs replacement?
A: Common symptoms include squealing noise during startup or under load, visible cracks or fraying on the belt surface, glazing (shiny appearance), poor alternator charging performance, or the belt feeling loose even after adjustment. If you observe any of these signs, replace the belt promptly.

Q: How tight should the V belt be after installation?
A: The belt should have a deflection of approximately 10-15mm (3/8"-5/8") when pressed firmly with your thumb at the midpoint between pulleys. Over-tightening can cause premature bearing wear on the alternator and water pump, while under-tightening leads to slipping and poor performance.

Q: Is this an OEM belt or an aftermarket replacement?
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.