This very popular Yanmar marine 4JH5-E 40 HP, Entered into the market in 2010 and is still in production. This raw water cooled, engine now has an Electromaax Serpentine Pulley Upgrade Kit that is very easy to install. Allow approx. 1 hour the first time you do this simple installation. When purchasing any Electromaax marine alternator the pulley can be installed for you at the factory. The new 10 groove serpentine (micro ‘V’) crank pulley simply slips over your current crankshaft pulley and is secured with the bolts supplied. The new serpentine water pump pulley simply replaces your original. When replacing the original Hitachi alternator with your new Electromaax Marine alternator the installation has been eased by utilizing the factory Yanmar connections making this upgrade “plug and play”.