85 merc 200hp blackmax - Regulated or Unregulated?

[JerseyJim]

While trying to diagnose issues on my merc - http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=17;t=029715 , i am confused as to whether my merc is unregulated as the clymers manual (45-225hp, 1972-1989) suggests:<br /><br />CAUTION: Sealed or maintenance-free batteries are NOT recommended for use with the unregulated charging systems on Mercury outboards. Excessive charging will cause the electrolyte to boil, resulting in its loss. SInce water cannot be added to such batteries, the battery will be ruined<br /><br /><br />anyone? bueller?

 

[nilsson]

Re: 85 merc 200hp blackmax - Regulated or Unregulated?

Hi JerseyJim<br /><br />I own a 1986 135hp version of your motor and have the same Clymer manual. None of the motors were regulated due to the RELATIVE lack of electronics in pleasure boats of the era. <br />As an automotive electrician I am somewhat hesitant to use SEALED lead-acid batts in boats due to fact that they cannot be checked/maintained and yes, they do boil under high alternator outputs (15amps continuous). These older motors only excerted about 6amps tops (Clymer doesnt mention, I checked Volts/Amps with multimeter). You wont damage any sounder/GPS equpment as they can handle the 16-odd Volts they push out at WOT.<br /><br />hope this helps<br />Nilsson