overcharging

[johnny mav.]

I have twin 200hp johnsn outboards 1989models at high rpm they are charging at 16 to 17 volts if I turn on all the electronic
equipment it drops the voltage to 13.5/14

 

[southkogs]

Let's see if you can get anything going here in the Johnson forum.

:welcome:

 

[Vic.S]

Sounds like a defective regulator(s)

Some useful information on testing in the CDI Electronics Troubleshooting guide. ( Page 7 et seq)

http://www.cdielectronics.com/wp-content/uploads/2013/02/CDI Troubleshooting Guide - 2012.pdf

 

[oldboat1]

Thinking (i.e., guessing) the batteries might not be fully charged to begin with (maybe due for replacement)?

Under load, the charging systems seem to do their job — don’t think that would be the case with bad regulators or stators. Additionally, it seems unlikely that both systems would go south on you at the same time. (JMO)

 

[Faztbullet]

Is your voltage gauge tied to both engines? How are batterys set up?

 

[ajgraz]

Is this a new "problem"? As in, it just suddenly started happening after doing something different before?

I don't know about older Johnsons, but all the older Mercs I've ever owned did exactly what you describe with the charging system, it's normal for them.

 

[Bosunsmate]

Is this a new "problem"? As in, it just suddenly started happening after doing something different before?

I don't know about older Johnsons, but all the older Mercs I've ever owned did exactly what you describe with the charging system, it's normal for them.

Yes my 1982 charges up to 17. something Volts. They dont have built in regulators. If you have a low maintenance battery and cant top up the fluid this can lead to trouble