1988 Force 125HP charging system???

[GregRLB]

Greetings all,

New guy here with a question about a 1988 Force 125 charging system. I recently wound up getting stranded on the water with a dead battery. This was a two fold issue as the battery wasn't up to snuff and has been replaced. The other issue was after getting the engine running again, the output voltage read 12.8 volts. The batter alone reads 12.6 volts so I figure that the additional .3 volts does not make for a properly working charging system.

I went through the steps according to the manual and did some diagnostics on the stator. Where I should have had some resistance on the ohm meter, it read a dead short. I also hooked up the volt meter to the to AC wires and with the engine running the stator was only discharging 5-6 volts AC.

I replaced the stator and put everything back together to get it started. The output AC voltage ranged from 25 volts at idle to 55 volts at the high end. Sorry, no tach to give you exact RPM's. Once I hooked up the AC wires to the rectifier, the battery voltage only read 13 volts, with 13.5 volts at the high end.

Having never had the need to take a voltage reading before, is 13 to 13.5 volts normal? According to the manual the output reading should be around 14.5 volts.

Now I did buy a new rectifier, which I've been assured is the correct part number. However, while the overall size of the rectifier is the same, the shape is slightly different with the newer one not having that 45? angle on one of the corners of it. Also, this new rectifier only has one AC terminal marking and the positive terminal marking on it. Can I assume that the position of the terminals are the same on the new one as the old one?

Any insight or help is greatly appreciated. Thanks in advance...

 

[pnwboat]

Re: 1988 Force 125HP charging system???

Generally speaking most of the square type rectifiers are marked the same. Both AC terminals are across from each other, the positive plus and negative or ground are also across from each other. When you measured the 13 to 13.5 volts what was the engine speed? Sounds like it was at idle. I have the same engine and mine is around 13 volts at idle but it goes up to about 15 + volts at full speed.

 

[GregRLB]

Re: 1988 Force 125HP charging system???

pnwboat,

The 13 volts was just above idle speed. I have no tach so I would have to say about half throttle the volt meter read 13.5 volts. This is the new rectifier and the only terminal markings are the ones visible in the picture.

So should the other AC terminal be diagonally across from the marked one, leaving the other unmarked terminal as the ground?

 

[GregRLB]

Re: 1988 Force 125HP charging system???

Another question which just arose is in regard to the band magnet that sits inside the flywheel. I took for granted that this just "sat" inside the flywheel since the first time I removed the flywheel the magnet came right out. Yet after surfing around the forum here I see that this should be glued into place.

So aside from asking whether this magnet should be glued onto the inside of the flywheel, what type of adhesive should, or could, be used? I have a slow cure 2-part marine epoxy but I'm not sure of it's adhering properties to metal. I also have some JB Weld which could be used as an adhesive and it bonds quite well to metal. Any suggestions or ideas? Thanks...

 

[maxum247]

Re: 1988 Force 125HP charging system???

pnwboat,

The 13 volts was just above idle speed. I have no tach so I would have to say about half throttle the volt meter read 13.5 volts. This is the new rectifier and the only terminal markings are the ones visible in the picture.

So should the other AC terminal be diagonally across from the marked one, leaving the other unmarked terminal as the ground?

Looking at the picture of your rectifier.
Clymer manual shows + with AC across from it at the top.
AC with - across from it at the bottom, so according to manual there on a diagonal from each other.

 

[maxum247]

Re: 1988 Force 125HP charging system???

Another question which just arose is in regard to the band magnet that sits inside the flywheel. I took for granted that this just "sat" inside the flywheel since the first time I removed the flywheel the magnet came right out. Yet after surfing around the forum here I see that this should be glued into place.

So aside from asking whether this magnet should be glued onto the inside of the flywheel, what type of adhesive should, or could, be used? I have a slow cure 2-part marine epoxy but I'm not sure of it's adhering properties to metal. I also have some JB Weld which could be used as an adhesive and it bonds quite well to metal. Any suggestions or ideas? Thanks...

Guy's at the local Napa store had the product I used! I just can't remember what it was, been about three years ago!

Question for you if I may! Does the magnet on your flyheel meet at the ends or is there a gap and does the magnet sit in the flywheel in a piticular position?

 

[GregRLB]

Re: 1988 Force 125HP charging system???

maxum,

Should this be the correct wiring of the rectifier then?

The magnet strip does have a slight space between the ends. I didn't measure it but I'd take a guess at just under ?" gap. The inside of the flywheel doesn't show any specific placement for the magnet or the gap in the ends.

 

[maxum247]

Re: 1988 Force 125HP charging system???

maxum,

Should this be the correct wiring of the rectifier then?

The magnet strip does have a slight space between the ends. I didn't measure it but I'd take a guess at just under ?" gap. The inside of the flywheel doesn't show any specific placement for the magnet or the gap in the ends.

The way the manual shows it your correct with the way you have them marked. I'd have marked them for you but didn't know how, little slow with the computer!

Thanks for the answer on the magnet question, mine has the 1/4 in. gap. I didn't see anything that indicated the magnet should be put in a certain way when I did mine but thought I'd ask to be sure. Thanks!

 

[GregRLB]

Re: 1988 Force 125HP charging system???

Just as a follow up, I glued the magnet to the inside of the flywheel. I also installed the new rectifier which gave me 13 volts at idle and 15.8 volts at full throttle. I think that the voltage is a bit high, but the battery is not a maintenance free one so I can add water to it should it start cooking some off.

Thanks for the advice and help with these issues.

 

[maxum247]

Re: 1988 Force 125HP charging system???

Glad to hear you got'er back in order.
The charging system on the 125 engines that we have are non regulated, but it sounds like your in about the right range from what I can tell.
Always use a serviceable battery, manual says not to use the maintainance free, my therory is because the charging sytem is non regulated it will boil down some and you need to be able to add to the battery once in awhile.

 

[Frank Acampora]

Re: 1988 Force 125HP charging system???

Just for future reference: The ignition power supply and the battery charging windings on the stator are separate. This means that if you have problems with a dead battery or you fry a rectifier and the ignition windings are still ok, you can pull start that engine with the ignition switch on. --As long as the magnet is still in place, it will start and run even if the battery is completely disconnected. However, disconnecting the battery or load is not recommended while the engine is running--it can damage the charging system. The battery is only used to power the starter motor.

 

[GregRLB]

Re: 1988 Force 125HP charging system???

Thanks for the info Frank! I did not know about that until finding this place and spending the better part of the night reading through the various threads in the Force repair forum. It's a wealth of knowledge you guys have here, much more than one would find in any manual!

As the owner/administrator of a reloading forum I should have known better to look for boat and/or outboard information on the Internet without checking a boating forum first. I'm glad I found this place and I'm sure I'll be back when another issue arises, which seems to be frequent when it comes to boats. I hope I'll be able to contribute some information back as well.

The next time out on the water I'm going to try to start the engine by hand with a rip cord. The flywheel does have a notch and groove in it to wrap a piece of cord around it. However, I think it will be a bear of a time to crank that by hand. I'll report back after trying it. Thanks to all again...

 

[Frank Acampora]

Re: 1988 Force 125HP charging system???

It's not too bad to pull over. First time, try it with the engine warm so you don't need someone to hold the chokes closed. Use a good stout cord with a handle of some sort or else you will damage your pulling hand. Use a cord about 4 feet long so you can get 2 wraps around the flywheel.

Turn on the ignition and put it in fast idle. Brace one foot on the splashwell, use two hands on the cord, and git "r" done. Do not have anyone standing behind you to get whipped by the cord.