Options for Upgrading to 160 AMP Alternator with a Serpentine Belt Kit

Our customer is an engineer, and as you can imagine, prepared several spreadsheets weighing the pros and cons of various alternators and the pulley systems that would work for our purposes.

“After talking with John from ElectroMaax at the Annapolis Boat Show in 2010, I decided to contact them to discuss my options for upgrading to their 160 amp alternator with a serpentine belt kit.”

“ElectroMaax had never built a belt kit for my engine, so I worked with them to provide the dimensions for the pulleys and the final product fits excellently.”


“Currently my wife and I are in the process of preparing to take an 18 month cruise throughout the Caribbean, U.S. East Coast and Canada. Our boat is a 2002 Beneteau 393 with a 40 horsepower Westerbeke 44A engine.”

“We knew that the existing Westerbeke 50 amp alternator wasn’t going to provide the power we would require to charge our batteries. Our plan is to save money by not spending time in marinas, but we needed a better way to generate electricity while we’re underway.”

Installation Steps

“Installation is very simple, to install the pulleys simply remove the four bolts that hold the water pump pulley and replace it with the serpentine pulley. The new crankshaft serpentine pulley bolts over the top of the existing crankshaft pulley allowing it to be installed without removing the crankshaft nut.”

“The alternator we used was a dual foot model and requires a few modifications to fit properly in the space provided on the Westerbeke engine. The existing alternator adjustment arm had to be replaced with a straight arm that can be purchased directly from Westerbeke (the part number is #43998).”

“John fabricated several precise spacers to help everything line up perfectly, and while it is a little confusing, John is very helpful with making sure everything is in the right place. Once the bolt is tightened through the dual foot alternator with the spacers in place, the belt is aligned perfectly.”

“After everything was tightened down, the engine ran great. The large serpentine belt doesn’t slip or wobble and I can’t wait to watch the large alternator provide the power we require while we cruise. A very special thank you to Rob and John.”

– Brad Fox, http://svjointventure.com/