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1995 Johnson 88 'stator output'

G

greendan

New member
I just replaced the rectifier on my 1995 Johnson 88 after fixing some ground wire issues. What should the ac output be while the engine is at idle? What should the rectifier output be going to the battery?
For some reason I think I had 35 vac and 14.8 vdc.
 
Sounds like you had the good sense to not try checking it with the battery disconnected. That would be a good way to blow another rectifier. OK, to the question. I can't say that I've ever attempted to check the AC voltage. All that matters is the DC. And that varies considerably on an unregulated system (yours is unregulated, right? ). Check it across the battery before starting the motor. Then start the motor and the voltage will slowly rise as the battery takes on a charge. It can go as high as 16V or more after prolonged running. That is normal on an unregulated system. Maybe not good, but normal. There are thousands of them running around out there at 16+ volts. If it bothers you too much, it is possible to add a voltage regulator.
 
Do not run a sealed maintenance free or gel battery on that engine if you can avoid it..the book for that engine calls for a 380 amp battery if i remember correctly...i dont even know if you can buy the recommended battery anymore..watch two things while running...your voltage will go above 16 and may peg a 17volt meter..as long as your tach operates correctly then the rectifier is ok...when the reading go to fluctuating the rectifier is on the way out...then one day you will read just battery output and no tach..time for another rectifier...a new one may last 2 days or two years..the one upside is the engine dont need it to run and you can get many starts on a
well charged battery..these rectifier only charging systems were no designed for todays top of the line batteries...a regulator for the engine is available and the mounting holes are there right behind the flywheel...maybe someone will jump in with the part number etc..i dont have it..as gator said dont worry about the ac output...it is the dc you are interested in...the ac will be there as you are charging off the peak of the pulses...its not a flat line dc output...
 
I'm not sure, but I think that is how some of the voltage regulators work, by adding a load if the voltage goes over a certain level.
 
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