1994 Force 120 question before buying stator

ObiwanKenobi

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I've spent countless hours on this forum gleaning wisdom and taking notes, but I need a little bit more info before buying a new stator for my 1994 Force 120. I'm including a good amount of detail, but what makes me think I need a stator the most is in bold below, so you can just scroll down to that if it's easier. I'm also hoping the detail I provide may help someone in the future who encounters a similar problem.

First, here are the symptoms and things worth noting:
- With the previous owner, the boat sat for about a year, but the carbs were thoroughly and professionally cleaned.
- Before the carb cleaning, the boat wouldn't start up right away. It always took two to three attempts. After cleaning, it still took at least two attempts.
- Once it was running, it ran quite well both at high speeds and low speeds. (But perhaps my ear isn't accurately "tuned" to how an outboard should sound.)
- It had a problem with stalling out while idling a few times, particularly when it was first getting going. This was a bit worse before it stopped altogether.
- One day, I tried to start it, and it just turned over and wouldn't fire up.
- Had a mechanic check each of the spark plugs, but there was no spark on any of them.
- No electricity in the boots, either--the junction between the coils and the spark plugs.
- Not a kill switch problem. Tested whether it was the kill switch by bypassing it at the switch itself and also by starting the starter by completing its circuit near the starter's base.
- The mechanic, while quite adept and with a stellar reputation, said I should replace the stator, the power pack, and the trigger because he couldn't figure it out. It's worth noting that he didn't really know how to use a multimeter: he only checked whether there was a "beeeep" when the electrodes were connected to each set of wires. When it beeped, he concluded that "the circuit was good." Also, because I live on an island in Belize, there are only a few types of motors out here. He usually fixes a motor by switching the suspect components with those of a healthy motor and isolates the issue via process of elimination.

Here's why I currently think it's the stator:
1. Following the procedures on OutboardIgnition.com, I did an ohms test on the appropriate wires, and here are the results:
Blue to Blue-white: infinity
Red to Red/white: 100

2. While the stator generally looks fine from the outside, there are a couple things that could denote melted insulation: some black smears on the inside of it and little bits of plastic around both the inside circumference of the stator and around the crankshaft. Here are a couple pics (they're big, but I figured that'd be better in case you wanted to zoom in):

First, the black smears on the inside of the stator:
image.tiff

Now, the bits of plastic on the inside near the crankshaft:
image.tiff

Any help will be greatly appreciated because, as I mentioned, I live in Belize (on Caye Caulker), so I have to be relatively certain I'm making a solid urchase. The cost of shipping is ridiculous, and I have to pay importation duties as well, not to mention wait a significant amount of time for the shipment. Thanks a lot, fellas (and ladies), much appreciated.
 
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pnwboat

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I am assuming that you have the "Mercury Switch Box" style ignition system. If you can include a picture of the side of the motor that has the ignition system components, it would help.

If it is the Switch Box style ignition system, then the Blue to Blue White winding should read 3250 - 3650 Ohms. Double check the resistance reading making sure you disconnect the wires from the terminals when reading the resistance. If Blue to Blue/White still reads "OPEN" or infinity, the stator is bad.

Be aware that the Switch Box itself could also be bad, however, you won't be able to confirm until you replace the stator.

NOTE: Can't see the pictures. If they are too large, they won't download.
 

jerryjerry05

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Welcome to the site.
You shouldn't be able to post pics until you have 5 posts.

You can however add pics through a sharing service, something like Photobucket??

Need pic of the switch box or a good description.

​The trigger depending on the year? Most likely won't be the problem.
Not many go bad.
​The older ones were good for the leads breaking under the shrink wrap at the connector.
​But that would only affect one cyl.

​You can have a bad stator and switchbox.

​Will wait for a pic or description before I add any more.
 

ObiwanKenobi

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Thanks, Pwnboat and JerryJerry. This is helpful already. Just went and made a few more posts in order to have more than five. I'll attach the pic of the side of the motor.
 

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jerryjerry05

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That's the newer system.
The connectors can get hot and short out.

Did you use an analog meter or a digital?


What flywheel? Pics?
What stator? Pics?
Unit will not fire: Disconnect the black/yellow kill wire AT THE PACK and retest. If the engine?s ignition fires now, the kill circuit has a fault-possibly the key switch, harness or shift switch. 1. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier. 2. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly. 3. Check the stator resistance and DVA output as given below:

Flywheel With Bolted In Magnets
WIRE Read To OEM Ohms CDI Ohms DVA Blue Blue/White 5000-7000 2200-2400 180V or more Red Red/White 125-155 45-55 25V or more

Flywheel With Glued In Magnets WIRE Read To OEM Ohms CDI Ohms DVA Blue Blue/White 3250-3650 500-600(a) 180V or more Red Red/White 75-90 28-32 25V or more (a) Encapsulated CDI stators will read 2200-2400 ohms from Blue to Blue/White.

Red Stator
WIRE Read To OEM Ohms CDI Ohms DVA White/Green Green/White 500-700 500-600 180V or more
Red Stator Adapter

WIRE Read To OEM Ohms CDI Ohms DVA Blue Blue OPEN N/A 180V or more Blue Ground OPEN N/A 180V or more
 

pnwboat

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Like Jerry stated, you have the later model Switch Box ignition system. The rectangular box/component in the center of the picture with all the wires going to it is the "Switch Box". It takes the voltage input from the stator and trigger coils to fire the ignition coils in the proper sequence. If you have a winding in the stator that is reading infinity or open, then that winding will not generate any voltage, thus no spark at the spark plug(s).
 

ObiwanKenobi

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Thanks, again, for the replies, fellas. Answers to questions below:
- I used a digital multimeter.
- The flywheel has the glued on magnets.
- The stator is a black one, model 398-8778A24 (attaching a pic of it as well)

I'm pretty positive the stator is bad because I went back and tested it again with the leads disconnected from the terminals--like Pwnboat suggested--and it is still reading infinity.

I think I'm gonna go ahead and order a new stator. Thanks for all the help. Very reassuring.
 

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jerryjerry05

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I asked about the meter as they suggest using an analog meter.
​I've never used a digital so I can't say if the results are different??????????
 

Nordin

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Measuring resistance you can use an analog or a digital VOM, does not matter what kind you use. But to measure voltage you need a DVA adapter (peakvoltage adapter) or a VOM that has DVA measuring.
When you have a DVA adapter you can use an analog or digital VOM, it does not matter.
What a DVA adapter do is to "freeze" the value so that you are able to read the value.

A simple explain is that the DVA is a capacitor that will be charged through a diod (halfway rectified) and it will discharge for a long time and you are able to read the value.

You can use a analog VOM with out a DVA, but you then must notice the topvalue of the voltage when you measure and that can be difficult.
 

ObiwanKenobi

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Good info about the different types of meters. I never understood exactly why a DVA adapter was necessary before. I read that multiplying whatever value appears on a regular multimeter by 1.41 would be sufficient, but from what you're saying, Nordin, it doesn't seem that multiplying by 1.41 would produce accurate results.
 

Nordin

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Your are a little bit on the right track when you multiply with 1,41. Your VOM measure shows a true RMS (root mean square) value, if you have a "good" VOM such as FLUKE or an other "no cheap" brand.

By multiply with 1,41 you calculate the AC peakvoltage value from a true RMS value.

The stator produce an AC voltage so what we are interested in to know is the peak value from the AC voltage.
The DVA adapter is as I stated before an elektrolyte capacitor with a diod.
What it do when we use it is that the AC voltage from the stator will be halfway rectified by the diod and then it will charge the capacitor with the peakvoltage as a "rough" DC voltage from the rectifier.

If you use a analog VOM without a DVA adapter you can catch to read the needle ......maybe! With a digital it will be harder to catch the value as it flip and flop up and down.

With the DVA the capacitor is charged and will hold the voltage for a while and you are able to read it.

The manufactor of the igniton system components report the factory spec. value as a DVA value and that why it is better to have a DVA adapter when you troubleshoot.
 

ObiwanKenobi

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Update and new problem... I bought the stator from CDI, threw it in, and the thing fired right up. (Thanks, guys, for the good advice.) I took it out for three short runs over the last few days. In total, we're talking about around 8 minutes of run time. Today, I took it out, it made it about 150 feet, then stopped. It just spins now, and there's no spark on any of the plugs. Based on research, my first guess is it's the power pack, which is known to fail when the stator goes. But here are some other things that happened that may provide clues:
1. When I started it today, it started, then stopped two or three times before starting and staying that way for about two minutes.
2. It was running rough, sounding like it was maybe misfiring, the first two times I took it out. This could be because it sat for two months and the oil and gas may have separated or water may have gotten into the fuel line, but I don't know. It seems like there's a good chance this is unrelated, especially because it ran pretty smoothly before it stopped running today. Also, the first time I took it out, there was a long, solid beep. The water from the tell-tale was more than "warm," but it wasn't too hot to keep my hand in, so I don't think it was over heating. That means it could have been water in the fuel line because that's the other condition that can cause a long, solid beep--according to what I've learned, at least.
3. The stator tests out well; it's within the Ohm range.
4. The ignition key is either turning it slowly or not turning it at all when I try to start it normally. However, when I connect the red power cable to ground in order to start it that way, it turns over very well. Still doesn't start, though.
5. The 20 amp fuse above the power pack (Is it actually called a "switch box," btw?) on the starboard side of the engine blew and I replaced it. I'm 95% sure that's because the mechanic was messing with a bunch of fuses while diagnosing the problem, however.

Is there a way I can test the power pack? Is there anything else I should test before springing for a new power pack? The magnets looked good and well-seated upon a quick inspection, but I suppose I could check them more thoroughly.

Engine details:
1994 Force 120 hp
Black stator
Glued in magnets

Thanks a lot, fellas. Any ideas would be greatly appreciated.
 

pnwboat

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First thing is to check the ignition kill circuit. Disconnect the Black/Yellow wire from he Switch Box. This will disconnect the ignition kill circuit. If spark returns, then you have a problem in the ignition kill circuit. The Black/Yellow wire is shorted to ground. This is how the ignition system is shut down when you turn the key to the OFF position.

NOTE: If the engine starts with the Black/Yellow wire disconnected, you will not be able to shut the motor off with the key. Either choke the motor until it stalls, or cover the mouth of the carburetors with your hand until it stalls.

If no change, try disconnecting the two yellow wires that go from the stator to the regulator/rectifier.

If still no change, then I would begin to suspect that the Switch Box has failed. I don't know of any way to test the Switch Box other than a process of elimination.
 

Nordin

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The only way you can troubleshoot the switchbox is to check that you have the right outputs from the triggers and the stator.
Then if you have this outputs correct you can check the output from the switchbox to the coils.

Output from box to coils should be about 210V DVA or higher in cranking speed. I do not have the values for the Mercury system in my head.
This values are for the Prestolite system but they use to be roughly the same for all OB CD systems. 200-300V DVA.

Do as pnwboat suggest at first, then check the inputs for the box from stator, trigger and the output form switchbox.
As you have a no spark issue at all plugs it sounds like you have issue with ign.switch, rectifier or the switchbox.
 

jerryjerry05

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The Force alarm system is for overheat only.
IF??? the buzzer went off it was HOT!!
Putting your hand in the water really means nothing.

​Now putting you fingers on the head would tell if it was really hot.
Your head gets hot but not so hot you can't keep your fingers on it.
​I bought a cheapo heat gun on the net $16 works great and if it gets dropped overboard? no big deal!!

​The slow turning over: pull the plugs and see if it still does it?
NO?? then do a compression test.

​They really don't have tests (OBI) for the switchbox but if the other tests are done right?
Then the process of elimination will lead to the pack.
 

ObiwanKenobi

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Thanks for all the replies. I tested the output to the ignition coils a few minutes ago and got nothing. However, I don't have a DVA adapter. (And it may take several weeks to get one because I'm on an island in Belize.) Does a lack of a DVA adapter mean my reading of 0.00 on the multimeter is completely invalid, or does that still tell me the power pack isn't putting out power? I first tested the multimeter using the battery and got 12.2 volts. I then connected the red lead to the green (+) wire at the pack and at the coil, and grounded the black lead, and I got 0.00 each time while turning it over. This tells me the power pack is shot--unless the reading is invalid because I don't have a DVA adapter.

Also, I'm turning it over by grounding the positive wire of the starter, so that eliminates the kill switch issues, if I'm not mistaken.

So does a 0.00 reading out of the pack without a DVA adapter tell me the pack is shot, or are there other steps I should take? Thanks, again, for the help, and I'm willing to bet this will help other folks down the road.
 

pnwboat

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The DVA allows you to get an accurate voltage reading. You don't absolutely need to use the DVA if you are just checking for any type of voltage output and are not concerned that much with the actual voltage reading.

Like Nordin said...if you have voltage going into the Switch Box, then you should have some type of voltage output going to the coils if everything is operating correctly.

The only way to disable or by-pass the ignition Kill circuit is to disconnect the Black/Yellow wire from the Switch Box. Starting the motor while by-passing the ignition switch does not by-pass the Kill circuit.

0.00 voltage on the wires going to the coils most likely means a bad Switch Box or the ignition Kill circuit is engaged (Black/Yellow wire is shorted to ground).

HHmm you're on an island in Belize.....time to think about a road trip and knock back a few Belikin premiums or maybe a Kubuli! LOL!
 

jerryjerry05

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ROADTRIP!!
Just so happens I'm free to help!!
I'll bring my DVA.

There is a post on how to make a DVA attachment for your meter.
​Use the search function.

​Also on Jan 25 2010 there is a good post on how to make one.
​bktheking posted it.
Can't get a link to it.
 

ObiwanKenobi

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(@jerryjerry and pwnboat: come on down!!! We have more than enough Belikins to go around! Haha!)
So, guess what, fellas? It was the stinkin kill switch after all. I unhooked it as suggested, got spark on all four, and it fired right up.

Took out the T-stat and tested it on my stove. I got it to open, but the water was boiling. When I took it out, there was a ton of salt in there and even some sand. I cleaned the T-stat opening and the stat itself, then soaked it in vinegar overnight. They don't have meat thermometers or candy thermometers on the island, so I had to use an oven thermometer when re-testing it this morning. But according to that, it began to move right around 130 degrees. Maybe it's fixed. I should be able to reinstall it and test it again today. But...

NEW PROBLEM: It's now idling like it's on crack. It never idles at a low RPM, but it sometimes revs really fast, then goes right back down. A bunch of times I sounded like it was knocking. It's like the timing is off. I was going to start a new thread, but because this may be related to the stator, I decided to keep it here.

I'm also thinking *maybe* the thermostat that wasn't opening yesterday was causing it to idle that way. Perhaps the higher than normal temps in the engine were causing it to combust prematurely. Not sure, though. Any ideas, fellas?

(Also, and this may just be my ears playing tricks on me, but the idling sounded less sporadic when the cover was on the motor. Still was idling too fast though.)
 
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