Balmar Serpentine Pulley Kit for Yanmar 4JH4 Series

The Balmar AltMount Serpentine Pulley Conversion Kit converts Yanmar 4JH4-HTE, 4JH4-TE and 4JH4-DTE engines to a J10 ten-groove drive.

Balmar notes the conversion reduces engine noise and vibration alongside improving load transfer. That is worth knowing because an overworked V-belt is a source of noise in its own right, and the improvement is noticeable on a boat where the engine sits under the saloon sole.

Load transfer is the primary reason, since a V-belt limits how much alternator output an engine can actually drive. Beyond a certain point the belt slips regardless of tension, and the alternator never delivers what it is rated for.

The kit covers the specific 4JH4 variants listed, so the engine designation needs checking rather than the series alone. Yanmar uses close model numbering across the 4JH range, and a 4JH3 or a 4JH5 is a different engine from these. Explore more alternator mounts and pulleys.

• Reduces noise and vibration as well as improving load transfer
• An overworked V-belt is a noise source in itself
• Beyond a point a belt slips regardless of tension
• Check the exact 4JH4 variant, not just the series