Charging problem - Evinrude OP 175hp 1998

Having a issues with my engine overcharging.


It starts off charging at 14.5v from cold and after running around for about 15 min @ 3500rmp and higher it starts jumping to 17,18 19+ v. It backs down if I reduce throttle to under 1000 rpm. I checked all the connections and even replaced the battery (it has and always has had ss nuts w lock washers). It is still doing the same thing. I verified it is not the gauge by connecting a volt meter right to the battery and got the same voltage reading as the guage. I check the voltage regulator connections and all looks good. I am assuming the voltage regulator is bad so I ordered a new one. But if that does not fix it , could the stator be the problem? I am quite baffled as to why a new parts like these would have gonna bad. But if anyone can think of anything else I should look at please advise. Thanks.


Just some history: In the spring I replaced my entire electrical systems with brand new CDI parts after having some igntion issues. NEW: power pack, optical sensor, wires, plugs, stator and regulator/rectifier.
Engine has been running great and even think it is using less fuel with the new ignition parts.

As it indicates, regulating the voltage to where it should be is the function of the voltage regulator. Why it has failed is anybody's guess but I feel you're headed in the right direction in replacing that regulator/rectifier assembly.

On a side note, has the tachometer been acting up?.... normally/usually caused by a failing rectifier portion of that regulator unit.

Thanks, the tach is fine. CDI tech told me that the stator does not charge the battery it only maintains it at the current level. The tech asked me how often I put the battery on a charger. I told him I never do. He claimed that if the battery is not kept fully charged the vr is constantly under stress and can have issues. I was always under the impression that the battery was charging when the engine is running. Electronics drain the battery so the battery should be topped off with a charger?. This makes no sense to me. Also, he told me agm/gell and maintenance free rv batteries are not compatible with ob engines. But mine are standard marine batts 550amps.

'' CDI tech told me that the stator does not charge the battery it only maintains it at the current level.''...your tech is wrong about that..

''He claimed that if the battery is not kept fully charged the vr is constantly under stress and can have issues''......your tech is right about that....the more current required from a regulator then the more heat and stress is applied to both the stator winding and the regulator...heat is an enemy of any electronic component....if you fish or boat today and are going to use the boat tomorrow and the regulator is working correctly there is no need to charge the battery over night..but if the boat is stored for any length of time the battery should be topped off before using..

Maintenance free batteries work fine if you have a regulator....they are a no-no if you have a rectifier only charging system....if you have a regulator your voltmeter should read around 14.8 when running...a non regulated rectifier only system will creep up and run 16-17 or even more....the rectifier will eventually fail...

[h=1]Battery Tender Plus 12 Volt 1.25 Amp Battery Charger is just one of many battery chargers that you can plug in and leave plugged in when your boat is not being used....i am not selling this one..i have used them on a houseboat and left batteries on them for years..this is in bold type because i copied and pasted..dont know why...[/h]

My engine has a rectifier/regulator (all in one unit). But I forgot to mention I always have a solar maintainer connected to the starting battery when not in use. One of those ones 1.5w from hardor frieght. I have always charged my house battery on the charger. The boat could sit for weeks with no use. When I put the old battery on the charger it indicated it was at 90% charge already an got to 100 in about an hour. I can't image a battery with that amount of charge would cause the regulator/rectifier to go onto overdrive and fail. Maybe 60-75% but not 90%. It is 3 yrs old. Also, had it load tested and it was in the green zone but just barely. In my opoinion my original batt was still good. So prob time to change it out anyway. I think the cdi reg/rect is just a touchy peice of garbage. I am trying to get them to replace it but its not worth the effort as it couold take 30 day for them to swap it . I ordered a new one (cdi) @170.00 and will send back the bad one. Best case is I have a spare. I will update my results when I put the regulator/rect in on Sat.

what is the part number on the regulator you have ordered?

Cdi-193-6048
same as the one that I installed in April.

dont forget to use the heat compound...

heat compound? please elaborate. There is nothing in the instructions sheet or in the engine manual about heat compound.

Ok, I see what it is but what do I put it on. The back of the regulator is inserted in the top of engine and is water cooled it will just get washed off.
It does not say to use it like other regulators
http://www.cdielectronics.com/wp-content/uploads/2013/09/IS-193-6048.pdf

Put in the new regulator, all is good. Also found the problem as to why it went bad. Turns out my battery switch was bad. For some reason I had voltage to the engine with the battery switch off. Probably the 2nd battery was connecting and disconnecting while running so the regulator was probably trying to charge one batt then 2 batts.

Took the switch apart and found corrosion in the housing. Hooked up the new battery directly to the engine and all is well. charging steady @ 14.2v @3500 rpm.

So I have to wake this thread up again. I have gone through 4 cdi electrons regulators now. Every time it the same thing . it runs fine for a while, then it starts overcharging after some use. eventually everything goes dead.
I am convinced these cdi regulators re just garbage and cant hand the heat of the 35amp systems. I have ordered the oem regulator form evinrude. Everything is new batts ground cables and battery switch.

The only other thing it could be is the stator right , I wet through cdi's ts guide but it does not tells you if the stator should be replace if anything fails. In step 4 what does it mean mark across the connections? I cant swap the yellow wire there in a connector bullet>>>>

1. Check the voltage on the purple wire while the engine is running, you should see the same voltage as the battery.

2. With all wires connected and the engine running at approximately 1500 RPM, check the DVA voltage from each yellow wire to
engine ground. The two readings have to be within 2 volts of each other (i.e. if one is reading 20 volts, the other should be 18 to 22
volts). If the readings are not equal, go to step 4. If they are equal, go to step 3.
3. Check the DVA voltage from the yellow wires to the red wire going to the solenoid. The two readings must be within 2 volts of each
other. If the readings are unequal, go to step 3. If they are equal on both this step and step 1, the rectifier (or rectifier/regulator) and
battery charging portion of the stator are OK.
4. If the readings are unequal, mark across the connection between the stator and rectifier on the low side. Turn the engine off and
swap the stator leads. Crank the engine up and retest. The component that has the marked wire with the low reading is bad.
5. At 800-1000 RPM, check output on the gray wire, reading should be at least 8 volts with a DVA meter. A low reading usually
indicates a bad regulator if the system is charging the battery.
Checking maximum

please describe your complete battery hookup including any and all devices and switches hooked to them..is that solar panel still hooked up?..please tell us how you use the boat...for example is it used and pulled after one day fishing or is it in the water and used days at a time with no external charger hooked up at night...if it is left in the water are lights left on while tied up or moored?..i do not think its a stator problem...

Thanks papyson , I use the boat once a week for about a 3/4 day of fishing. When not is use it is stored in a rack with the batteries off. I have dual batteries with a blue sea 1-2 both-off switch both positive leads to the switch and neg cable go to a buss bar


Both batts are brand new, interstate marine 550 cca type 27 batts. This is what CDI told me to use when I complained to them.
I not longer use the solar maintainer as it was stolen.






Whats connected.


All the positive leads are connected to the switch common: both batt positives , engine pos, boat electrical pos (feeds the bots switches, electronics, ect).




I have some individual items connected righ to the batts as well.


Rear bilge pump is connected to batt 1, so it has power to pump out if the switch is not on. the maulay wire goes ot the helm.


The trim tab control box is mounted near batt 2 is directly connected to batt 2. I rarely run on batt 2 so I just take that one home and charge it every few weeks.

All grounds are connected to buss bar mounted next to the batt switch. (engine ground, batt 1 and 2 and boat ground ,ect)

no sorry typo.... just the pos for the electrical, the pos from the batts are connected to 1 and 2 on the switch. The batt negs are connected together and inline to the engine ground.

and What do I use for the DVA testing of the stator, DC or AV setting?

I dont see this as being a stator problem...what i think is happening is here is high current bring drawn from the charging system...the first thing i would do is change how i treated the batteries...when you put the boat in the water to use it both batteries should be fully charged with an external charger...to rely on a boat charging system to recharge a battery (or in your case two) is wrong...lot of people do it but they are putting stress on the system... just because a battery will turn and start an engine does not mean it is ''almost''charged...it can be run down to the point where it draws a lot of current once the engine starts...

here is what i would do if i was you...start with both batteries fully charged...for trouble shooting purposes i would do the following....disconnect everything from he ignition battery except the bilge pump...isolate it from everything but the motor and pump...disconnect the switch completely.. hook everything that you need to the 2nd battery...have two good batteries fully charged and recharge to full between outings in the boat... use it like that and lets see that you got..

as i said i think an excess current problem....this could be caused by anything from a battery to a load problem(either an excessive load or a problem in a load device) to a wiring problem..(either a problem such as a short or a wiring error)..

ok, so I did that , I put the engine on an isolated batter that I fully charged 100% with just the battery and the pump. I put in the OEM new regulator. Started the engine.

It charged @ 14v and tach worked for about 3 min everything went dead again. Its weird that the tach shows cranking rpms until it kicks over, then nothing. This is very frustrating.

i assume the engine kept running with no change after the failure..is this correct?...where is the negative battery lead connected to the engine..the wire going straight to the engine or to the ground block ?have you checked the ground at the engine?have you unplugged the large plug going to the controls and inspected it for corrosion etc?you also have a unfused purple wire going through that plug to the ignition switch...my diagram shows that wire coming off the rectifier terminal block....i would also check the switch for loose connections or wires too close together..

have you added any devices that are wired into your console wiring?

it may seem like i am shotgunning the problem and i am at this point...the reason is if you are losing regulators every time a decision is made (actually no decisions are being made) it is damn expensive...

if i go back to your original entry the problem was ignition and not this problem before you replaced all those parts..is this correct?...at this point did you replace a rectifier with a regulator?the reason i ask is the diagram i am looking at shows a rectifier only charging system..i said i did not suspect the stator but if the engine has two options on the type charging system then there are two part numbers out there for the stator..you also state in the first entry that the charging voltage went to 19+ volts...a regulator should hold at 14.8...with the correct stator and correct regulator for that stator the voltage should never go higher than 14.8 or so...i guess its possible with an open wire causing a no load condition but i have never experienced it...when you talk to CDI again i would ask two questions...1.will a no load condition knock out this particular regulator?...2..what is the correct stator for this regulator?

when i suggested isolating to just the ignition battery i meant just that...no tie in with the 2nd battery at all including the ground...no possible connection at all onto the 12v net of the engine...that goes for that switch also..

yes the original problem was ignition yes. I replaced everything. statot regulator, powerpack ect.

after replaceing these items the issues went away. but the new issue of overchargin arose. overcharging resulting in blown regulators

so now I have issues that may be pointing me to the new stator,
I verified all the part numbers. they are correct for my engine.
this morning I wentback down to the boat to test the stator. the engine stared up and it was charging and tach running fine... from cold.
ok what going on?

. I let it run for about 20min and everything is good, I take it out for a run.
Aso soon as I hit the throttle everything goes dead. again. shut down restart still nothing.
I do the dva test on the stator yellow wires and I am getting no voltage commin out of the yellow wires. Alos when It do a resistance test on the
yellow wires on the stator , I get nothing, I should get something right? voltage regulator bench tests fine. is it possible this stator is overheating?

sounds like it....your meter on ac when you read the stator voltage?...afor your purposes you do not need a dva meter6-pole stator with the flywheel spinning at 300 rpm (a good cranking speed) will put out 60Hz on the charge coils, which is just perfect.

a six pole stator will put out at 60 cycle at 300 rpm...so for this problem you dont need a dva meter..you basicly just want to see of the stator is putting out...if you want to get specific then just multiply the reading by 1.41...

if it is the stator then the question is why it went out...is it the correct stator..did it have a load that caused it to run hot and eventually fail?..current causes heat..stators dont like heat...

if this is the problem you may have some good regulators laying around.....

found the problem, I took off the stator. One of the yellow wires has a bad contact on the stator
when doing the continuity test, I get tone but when I wiggle one of the yellow wires it goes off.
someplace where the yellow wire makes contact with the copper coil in the bedding compound it loses connection.

excellent !!!!!!!!!

another update on my findings. Being frustrated with having to buy another stator I figured I would try to figure out what happened his one.

After chipping off the epoxy covering the connection from the bad yellow wire to the copper winding, I discover it. The connection was shotty at best.
They had very little solder holding the wires together, they pulled apart will little effort. But were not burned. I am sure over time this connection just fell apart from heat and engine vibrations. I am suprised it even lasted 6 months. Engine vibration and heat and the cheesy connection.. get what you pay for. So how this caused the overcharging still baffles me. I guess a loose connection right to the voltage regulator probably caused them to blow up.

So, I go to work reconnecting the yellow wire to the copper coil. I get it all soldered back nice and tight using the core of a butt connector.
Put some new epoxy over the connection. Now the continuity test works fine.

I don't want to put this back in the engine but do you think it I should save it for a backup. Or get rid of it.? I bench tested it and all numbers are within range.


Another thing I noticed it when I ground tested it I had a real hard time getting a good contact to the stator frame with the paint on it.
Some advice to anyone putting on a stator like this in your engine, make sure you get a good ground contact to engine and scrape some of the paint off the areas that contact the engine block.

I am thinking this stator may have suffered from weak ground as well.

Thanks for your input popyson, you helped get me in the target zone to this issue.

if you got a good connection i would not hesitate to use that stator...its nothing more than a coil of wire..

i think i would run the boat with the ignition battery still isolated for a few hours at least...its possible that another problem will pop up and it will simplify things..there has been a lot of activity and sometimes that results in a second problem..but you found the root cause..

as you can probably tell by now i am not a great fan of battery switches anyway....load the 2nd and maybe third battery with anything you wish but leave my ignition and charging system alone is my motto..then take good care of the batteries and put them in the water fully charged and you are good to go..and more importantly get back in..