The Yanmar belt tensioner and idler pulley kit further enhances the performance of a high-output alternator, like the Cruiser and GenMAAX line of Saddle Mount (SM) alternators, and is specifically for Yanmar JH Series of marine engines. The tensioner is a simple device that eliminates the need to tension the belt using a stick or screw drive that requires the installer to have three arms! Now with the turning of a bolt you can easily achieve the perfect belt tension for your Yanmar engine. ***NOTE: THE IDLER PULLEY DOES NOT FIT ON THE 4JH3 SERIES OF ENGINES!
The idler pulley is a universal fit on most Yanmar JH Series marine engines and does not require any additional brackets. It fits under the plastic belt cover and adds extra flexibility along the belt’s length. It is a perfect solution when the raw water pump resides on the front, lower right-hand side of the engine to provide extra belt clearance, and the extra belt wrap on both the alternator and crank pulleys allows for a greater alternator upgrade while keeping the belt in perfect tension and away from the raw water pump.
Key Benefits: The belt will never slip as the alternator is held firm. It helps reduce belt dust and eliminating slippage greatly increases belt life. Simple replacement bolt on – no additional brackets. Universal fit on most Yanmar marine engines. Fits under plastic belt cover. Engine runs quieter. Maintenance free performance when belt is properly installed and tensioned. The tensioner on its own will not eliminate belt dust!
Note: For higher amperage alternators (over 100 amps) the tensioner needs to be combined with a Serpentine Pulley Upgrade Kit manufactured by ElectroMaax for your specific Yanmar engine.