200gt Johnson charging problems

[Edwardnizz]

please help,, i bought a great old boat,then one day i left the battery switch on and when i went to use it the battery was dead. i used jumper cables to charge the batteries and got everything working.
i went on the water for about 2 hours the last hour i noticed my tach wasn't working and my batteries seemed to be draining. the voltage meter went all the way down!! luckily i made it back to the ramp before it died but at the dock i went to restart it and sure enough it was dead.
could i have messed something up jumping the battery?
the tach was always working intermittent but now not working at all and the battery definitely isn't charging.
im sorry if this might have been covered before but i really need help. im not that familiar with this motor.
its a Johnson gt 200hp i think its an 1988 motor.
i appreciate any help i can get

 

[Dhadley]

Re: 200gt Johnson charging problems

Chances are the rectifier / regulator is bad. It's water cooled and the block probably isn't venting like it should. Therefore there is air trapped at the top of the block and that causes the reg / rec to overheat (it cools in water not air).

You'll probably want to address the issue asap because there is a chance the wiring can catch on fire. Once you get the reg / rec changed the tach will, most likely, work again. An intermittent tach is usually the first sign of a reg / rec going bad.