Balmar AltMount Serpentine Pulley Conversion Kit for Yanmar 4JH4-HTE, 4JH4-TE and 4JH4-DTE Diesel Engines

High-Output Alternator Drive Upgrade for Marine Diesel Systems

Upgrading to a high-output marine alternator is one of the most effective ways to rapidly recharge large onboard battery banks. However, factory standard V-belts often struggle to handle the mechanical load generated by high-amperage charging systems. The Balmar AltMount Serpentine Pulley Conversion Kit is engineered specifically for Yanmar 4JH4-HTE, 4JH4-TE, and 4JH4-DTE marine diesel engines, providing greater load transfer than the standard V-belt drive.

When high-capacity alternators are paired with traditional V-belts, the excessive load frequently leads to belt slippage, squealing, rapid wear, and black belt dust accumulating inside the engine bay. By converting your Yanmar engine to a 10-groove (J10) serpentine belt system, the load is distributed evenly across a wider surface area. This improves grip and power transfer, and Balmar notes that AltMount kits also reduce engine noise and vibration.

Engineered for Precision Alignment and Reliability

Unlike makeshift bracket modifications or mismatched aftermarket pulleys that can cause severe vibration and premature bearing failure, the Balmar AltMount kit is designed specifically for the listed Yanmar 4JH4 engines. Proper pulley alignment is critical in harsh marine environments; even minor misalignment can shred belts under heavy electrical loads, leaving your vessel without charging or engine cooling.

This comprehensive conversion package includes the required pulleys, mounting hardware, and two 46" (approx. 1168mm) J10 serpentine belts. The inclusion of a dedicated spare belt ensures you have an immediate replacement onboard, reducing the risk of downtime when operating in remote anchorages.

Installation fastens a conversion pulley over the existing crank pulley and replaces the water pump pulley. Balmar recommends that every AltMount kit is installed by a qualified professional.

Key Features and Kit Inclusions

• Direct Engine Compatibility: Purpose-built for Yanmar 4JH4-HTE, 4JH4-TE, and 4JH4-DTE marine diesel engines.
• Heavy-Duty J10 Profile: Includes three 10-groove (J10) pulleys designed to drive high-output Balmar alternators.
• Alternator Compatibility: Balmar designs AltMount kits for its 6-Series and XT-Series alternators. Balmar notes that an older AT-200A alternator may need a longer belt.
• Dual Serpentine Belts: Supplied with two 46" (approx. 1168mm) circumference J10 serpentine belts, providing one for immediate installation and a critical spare for your onboard toolkit.
• Complete Hardware Package: Comes with dedicated mounting hardware to ensure accurate belt alignment and secure installation.
• Smoother Running: Balmar states AltMount kits improve load transfer while reducing engine noise and vibration.

Ideal Applications for Marine Electrical Upgrades

This serpentine conversion kit is an essential mechanical foundation when upgrading your vessel's electrical generation capabilities. It is particularly well-suited for:

• Cruising yachts and powerboats upgrading to a high-output Balmar 6-Series or XT-Series alternator.
• Vessels transitioning to lithium (LiFePO4) house battery banks that demand sustained, heavy-duty charging loads from the engine.
• Replacing the factory V-belt drive where a high-output alternator needs greater load transfer.
• Commercial and recreational marine operators seeking dependable engine-driven charging.

Upgrade Your Yanmar Alternator Drive System

Ensure your marine engine can safely and efficiently drive a high-output charging system. Equip your Yanmar 4JH4 series engine with the Balmar AltMount Serpentine Pulley Conversion Kit for reliable power generation on the water.