Home › Forum › Ask A Member › 1983 70 hp Johnson overcharging
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vintin.
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February 18, 2016 at 8:22 pm #3657
Gentlemen,
I have a 70 hp Johnson that has been overcharging a long time. I have been ignoring it but it continues to climb. I have read that they did not have a voltage regulator, rather using the battery as a residuary of unused power. On the net I came across a devise called a "regulated rectifier" made by CDI. I have not had good luck using anything other than OMC parts (original manufacturer). Does anyone have any experience with this company or this problem?
Other than that this 33 year old engine runs pretty well. Thanks for your consideration!
JimFebruary 18, 2016 at 9:36 pm #32118CDI is a well known company producing quality aftermarket ignition parts. Yes they have a new product–a regulated rectifier. Fits in place of the original rectifier but has built in voltage regulation.
EDIT: CDI part number for the standard rectifier is 153-3408. For the regulated one, change the number to 193-3408. Most Evinrude dealers are aware of CDI. On-line, iboats.com sells it. And others, I’m sure.
February 18, 2016 at 10:22 pm #32120looks like a good product but warning says to keep away from " maintenance free " battery as OVERCHARGING will result 😯
Joining AOMCI has priviledges 🙂
February 19, 2016 at 12:24 am #32124CDI is a reputable company, and is actually the only American company making electrical and ignition parts. I have installed the regulator/rectifier unit you are referring too, and it seems to solve the ”overcharging” problem on this style charging system. I have also installed these on some older Mercury outboards with the non regulated system as well. Seems to work great.
February 19, 2016 at 3:15 am #32127That "issue" has been around for decades on any OMC engine produced with a simple rectifier.
The least expensive "fix" for it is to simply turn on your running lights. That keeps the voltage pretty much in check for the duration of most trips. Got a fishfinder? Turn that on as well if you want.
I remember groups of old guys from Naples coming in to the Miami Boat show every year, cornering one of us and telling us we built a defective engine for this reason and what were we going to do about it. We gave them the same answer every year.
Now, those guys were different in that their fishing grounds for big grouper would be 50 miles or more offshore in the Gulf and by the time they got out there the batteries would be hovering over 16volts sometimes and losing water. Simple cure for a simple issue.
Funny thing was that the same guys would come in each year and pick a different guy to hammer on. I worked 25 Miami Boat Shows in a row, never missing one. Eventually you get to know guys like that and they almost always turned out pretty nice.February 19, 2016 at 5:00 pm #32153Electronics parts will fix your overcharging for ever. Remember the guys who ran with the additional center light in the grill? That was to keep from overcharging. Now, look up a zener diode. This little component has a set voltage built into it in many voltages. Install this device on the output cable of your generator weather or not an A.C or D.C. generator & it will shunt the extra voltage. Go for a 13.8 voltage & it will block any extra voltage the generator builds. I looked them up in Radio Shack & they are described as; Gas tube surge voltage protectors. Used for overvoltage protection with high current capabability, three electrode types, including fail safe & vent safe options. This gives a guy a base line to start with. It basicly blocks any overvoltage & lets any voltage below the set point to pass. It is a raw form of regulation that will stop over voltage curing the issue at hand. For questions go to a genny rebuild store, they know what will function.
Good luck!February 19, 2016 at 9:23 pm #32167Gentlemen,
I appreciate the suggestions and guidance. We are looking forward to spring and a little trouble free boating. Thanks again!
JimFebruary 20, 2016 at 12:10 am #32170Keep in mind that there may be a problem with your wiring/battery contributing to this problem. I am assuming you are basing your judgement on high boat voltmeter readings. This engine only has a 6 amp system, so it’s not likely to cause a high voltage/overcharging situation unless there are no other boat accessories used, or perhaps the battery is under-sized for the application. Check the battery connections/wiring, high resistance could help build up voltage in the system. Be sure to check the battery acid levels, low levels will cause high voltage as well.
Needless to say, there is nothing wrong with adding the regulator kit others have spoken of, or just turning on the lights while traveling at high throttle settings, as Casey mentioned. But, just wanted to mention other problem areas, a bad battery/low acid levels could explode.
One final thought I should have mentioned first….You dash voltmeter may be inaccurate.February 20, 2016 at 2:41 am #32174The CDI regulated rectifiers sure seem to make sense. Battery life and also alternator life should be extended. It’s got to be easier on the alternator to put out less current as the battery charges up. Turning on lights is guess work unless you’re running a volt meter and even then the alternator is putting out full current causing increased drag and wear on it’s internals.
It seems the zener diode method of ‘shunting’ excess voltage would also lead to the alternator putting out maximum current even when the battery is fully charged.
It’s likely minor but an alternator putting out less current is easier for the motor to turn in the case of the older belt driven types and even a stator putting out full current puts a larger load on the motor. I doubt a measurable difference in fuel mileage could be measured though.
An over voltaged electrical is going to shorten the life of lights and may not be good for GPS, etc.
This seems like a good area to adopt the latest electronic technology.
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