1990 Johnson 120 HP outboard voltage too high.

[Coffeeman 59]

I have a 1990 Johnson 120 HP outboard. When cruising it's charging rate climbs to over 17 volts on the dash meter (16.7 on my multimeter) Sometimes after starting the dash meter is at 0 then climbs after a few minutes. Have cleaned and tightened the battery leads. What would cause this over charging? How can I correct it? It drops when I use the power trim but climbs back up in a minute or so. Is there a danger of burning something up?

 

[racerone]

What kind of battery is installed ?----I would replace the rectifier / regulator.

 

[Coffeeman 59]

Battery is a NAPA lead/acid. Thanks for the advice. Hope the parts are still available for a 1990 engine.

 

[racerone]

Pretty well al parts are available if you know where to look.