In order to fix the charging problem on the boat motor I had to replace the voltage rectifier. It converts the AC current from the stator to a DC current. I checked the price on the proper Mercury part and it was $117.50! What a complete ripoff boat parts are. A bit of research on the net and it turns out these rectifiers are nothing special. I picked up a $4.95 35amp Bridge Rectifier from Jaycar. It wired up nicely and even screwed back on to the original mounting holes.