Hello all. Just purchased a 2005 Mainship 30 pilot 2 The Tach works fine for about an hour and then gets erratic and stops. The boat has a 315 Yanmar. Where is the sending unit located ? Also, has anyone installed a fresh water flush on the raw water intake for this style boat? Thanks in advance for any and all information.
My tachs get their signal from the alternators. Sometimes, when the alternator output drops as battery charges, the tech signal will be lost. Try increasing the load by turning on a high draw item like a heater on an inverter or a high demand 12v item. As the alternator output rises to meet the new demand, you may see the tach signal return.
__________________ My boat is my ark. It's my mobile treehouse and my floating fishing cabin. It's my retreat and my respite. Everyday I thank God I have a boat! -Al FJB
Our Yanmars (370hp 6LYA-STP) have a sending unit on the flywheel housing. I bumped it once while opening the seacock and lost the tach signal on one engine.