Bad CD Box? - Need help confirming

[kcantlon]

Hello all!

I have a 1989 Force 125hp Outboard and I need some help.

Recently had it on the water and was experiencing hard starting, rough idle, low power, and high rpm surging (+/- 500rpm)

I had just replaced the spark plugs prior to this lake trip, so I started by pulling the plugs to check their condition (~3hrs old).

1. Plugs 1 & 2 look normal, plug 3 looks almost new, plug 4 looks brand new. (See pic, plugs 1-4, left to right)
2. Cranked the motor to check for spark. All plugs were sparking well IMO. More blue on 1 & 2.
3. Checked compression. ~120psi on all 4 cylinders.
4. Checked, cleaned, and sanded ALL electrical connections.
5. Re-checked spark. Same as before.
6. Put motor on muffs, fired it up, and let it idle. Rough idle... and heavy smell of raw fuel from exhaust.
7. Pulled the plug wire off of cylinder #4 while running with no change in performance.
8. Removed plug #4 to see if it was "wet" with fuel. It was soaked with fuel.

I am convinced that the CD Box that feeds coils 3 & 4 is probably bad, but I am surprised I am still seeing a fairly strong spark? I understand plugs will not arc under compression if getting supplied with low voltage.

Are there any other checks I should do before investing in a new CD Box? Could this be a trigger issue?



Thanks,
Kyle

 

[tommarvin]

Welcome, we have a 1988 125hp and you know a lot , your good to diagnose this much.
Go to www outboardignition.com or cdielectronics.com they have all troubleshooting and testing on all ignition parts, you can test with ohms, but they recommend using a DVA /peak voltage meter for our ignition parts.
I would only get cdi electronics ignition parts, outboard ignition is a dealer for cdi.
There are two switch's in our cd boxes, and one side could not be working,half out,and the other side works, which side is it, it doesn't matter you have to buy a new cd box.

 

[Nordin]

Have you tried to pull plug wire for #3 and see what happens?
If no changes the #3 also faulty. If that is the fact there are two things to check.

As both #3 and #4 not perform they have two common things.
1. CD module #2 feed the #3 and #4 ignition coil. Swap CD moduls and look if the issue moves to cyl. #1 and #2. If it does CD modul is bad.
2. The stator has three windings . One for charging the battery and one for charging the capacitors in CD modul #1 feeding ignition coil for cyl.1 and 2.
The third Winding is feeding CD modul #2 for cyl.3 and 4.

Switch the stator wires for CD modul 1 and 2 and see if the issue moves to cyl.1 and 2. If it does the stator is bad (winding for CD modul 2)

Outboardignition has the troubleshoot guide and maxrules has the engine wiring diagram.

 

[jerryjerry05]

All 4 should have bright blue spark.
​Try swapping the packs around.
Try swapping coil leads.#2 and #3
l​Outboard ignition.com sells ignition parts and your motor might have their parts already.
Their test specs on stators is different than the factory.
Make sure you know what you have.
You can do the basic tests with a regular analog meter.
But voltage test need special equipment.

e-bay for electronics. way cheaper than OI.com

From CDI: if 2 cyl from same pack don't fire then the stator is bad???

 

[kcantlon]

Thank you SO MUCH for the responses. I got the multimeter out this morning and did some checks.

Engine has all original electrical components.

Stator resistance readings: (OEM Spec says = 680 - 800 ohms)
#1 to #2 = 1178 ohms (High)
#3 to #4 = 744 ohms (in spec)

Trigger resistance readings: (OEM Spec says = ~50 ohms)
#1 = 47 ohms
#2 = 48 ohms
#3 = 47 ohms
#4 = 48 ohms

Rectifier tested good: ~0.5v in the 4 directions it should and "open" in the other 4.

Before I begin switching around CD Boxes and Stator wiring to chase the change in performance, does this data show something faulty?

The first stator reading is high, but I am having issues with cylinders 3 and 4. Related?

I also plan to pull the flywheel and verify the magnet is not slipping/un-glued.

Thanks,
Kyle

 

[Nordin]

Yes, all except for #1 and #2 stator are in spec. Are you sure the stator which i out of spec is connected to #1 CD module?

Try to swap the CD modules, if no change check the magnets.

 

[Jiggz]

I recommend starting with the easy tasks first. Switch the blue and yellow wires from the stator feeding #1 - #2 CDM to that of #3 and #4 CDM. If problem follows, you have a bad stator or there is a problem with the stator wiring. If the problem did not follow, it means you have good stator and no need to re-switch things back.

Next, switch #1 and #4 ignition coils first and see if the problem follows. If it does it means #4 coil is bad. If it doesn't that means both coils are good and you can just leave it as it is. Meaning you do not have to re-switch them back to their original locations.

Next switch the CD modules. Again if the problem follows, meaning the spark is now on #3 and #4, then you have a bad CDM. If problem did not follow, then both CDM's are good and you do not need to re-switch them back.

Remember, except for the switching of stator wiring, the other switching involve physically removing and re-installing components and NOT JUST WIRES! Make sure you take proper note of the original wiring or even better take pics of it before moving things around.

 

[kcantlon]

**Update**

I switched the following items with NO change in performance. #4 cylinder not sparking under compression. I know this because the engine runs fine with #4 plug wire off, #4 plug sparks in atmosphere, and it always looks brandnew and soaked in fuel when I pull it out after running the engine.

1. Swapped stator wiring. No change.
2. Physically swapped coil #1 with coil #4. No change.
3. Swapped* CDM #1 with CDM #2. No change.
4. Verified magnets are not slipping on flywheel.

Does this pin point it as a trigger issue?

* when I say swapped, I mean that I switched the coil wires and all of the trigger wires on the connection board. I didn't physically move the CDM's on the bracket or mess with the stator wires for the switch.

Help

Thanks,
Kyle

 

[Jiggz]

Trigger is the only thing left. So the next move is not to switch but to do a visual check of all the trigger wires going into #4 . Resistance reading is not good enough. Sometimes the problem is that the wire is so small that even one strand still connected can give you the correct resistance reading but will not allow enough voltage to pass. Sometimes, the problem is with the butt connectors also if used. Or it could be a pinch wire that gets shorted to ground.

I hope when you said "No change" you meant that #4 plug continues to NOT fire or have sparks and not necessarily the engine performance or the misfiring not going away. For if you swapped the CDM's, the coils and the stator wiring and #4 continues to not have spark, then the only thing left is the trigger unless that spark plug is faulty to start with. It will also be beneficial if you have one of those inline spark tester. It costs less than $10 (auto parts store) and will be helpful in identifying if you actually have sparks or not.

Finally, the last thing you can do is to get a DVA adapter and read output voltages on the trigger, CDM, and coils.

 

[kcantlon]

Thanks Jiggz.

Yes, let me expand on the "performance vs. sparking."

I am able to visually see a spark from each and EVERY plug when it is removed from the cylinder head and I crank the engine. The spark colors all appear to be about the same... brighter blue on cylinders 1 & 2, but barely.

However, with the motor idling on muffs, I have yet to experience any change in performance the whole time with plug wire #4 on or off the spark plug. Also, everytime I remove this plug, it continues to look brandnew like the first photo on this thread. If I unplug cylinders 1, 2, or 3 there is a very noticeable difference in idle and the engine almost always dies. Plugs 1 & 2 cause the most effect when unplugged.

Would an inline plug tester ID a plug not sparking under compression? I figure it would since it's likely just reacting off current flow. I will get one of these and find out!

I also switched the actual plugs around on the head to see if the dud cylinder would move and it didn't. So I don't think I have a bad spark plug.

Just to recap: I believe I have executed all possible troubleshooting ignition component switch-a-roos without ANY effect.

I have the flywheel off now to visually inspect the trigger, stator, and magnets. It all looks good and intact.

I will keep everyone posted on my search.

Thanks again!
Kyle

 

[kcantlon]

**update**

I bought an in-line spark tester to tryout this evening.

Hooked it in-line on every plug wire and fired the engine up. It would flash on ALL 4 cylinders like all is well...

I wanted to see if it would flash while hooked to a non sparking plug. So I just hooked it in-line on coil #4 with a spare spark plug hooked on the end and just hanging in mid air, not grounded.

Fired the engine up and the in-line tester was flashing away, with no spark on the obviously ungrounded plug.

I am going to work on obtaining a DVA adapter next. Does anyone know what peak output voltages I should see from a good stator, CDM, and coil while the engine is idling around 1000rpm?

Thank you to EVERYONE that is watching and trying to help. I am learning a ton and this forum is great!

Thanks,
Kyle

 

[Jiggz]

I'm not one of the believers that a spark plug will indicate spark out of the cylinder but will not spark under compression. If you see spark while #4 spark plug is out, it is obvious the cause of non-firing is the lack of fuel (assuming you have good compression on the said cylinder). This can be caused by a broken reed which will affect the amount of fresh air-fuel oil mix going into the cylinder but will not affect compression.

To test if #4 cylinder is getting enough air fuel oil mixture, do the wet paper test. Get a clean sheet of paper and placed it infront of #4 cylinder (plug removed) about 2-3 inches away. Just make sure you stay out of the way for safety. Have someone crank the engine over for about 3~4 times. Did the paper got wet with fuel oil mixture? For comparison do the same with #1 cylinder. is the area of wetting about the same?

If the wetting on #4 cylinder is barely and not as much as #1, there is a good possibility you have broken reeds or reeds not sitting properly anymore on #4. Post your diagnosis.

 

[kcantlon]

10-4! I have experienced the on/off sparking scenario with an old '78 YZ400 dirt-bike once upon a time... Or at least I thought.

I will try the wet paper test this afternoon and report back with pics. I will also re-check the compression.

It should be noted that I switched the #1 plug (dirty with carbon) with the #4 plug (still clean) and ran the engine for about 5mins last night. When I removed the plugs: the dirty #1 plug was just about washed clean and dripping in fuel after being in the #4 cylinder, and the clean #4 plug now had carbon cooked onto it from being in the #1 cylinder.

I also pulled the bowl off the bottom carb to ensure it was getting fuel and no jets had fallen out. All was intact with a bowl full of fuel. The air/fuel mixture screw is at roughly the same adjustment as the top carb.

One other tidbit of info, initially in my troubleshooting when I only had plug #4 out to check for spark. I had someone crank the engine while I held the plug grounded to the cylinder head directly next the to spark plug hole, well long story short I experienced a small fireball from the plug igniting fuel vapor that shot out of the cylinder.

Thanks,
Kyle

 

[Jiggz]

Thanks for the update. Now it seems it is not a case of lack of fuel on #4 but more of a water intrusion that is steam cleaning the spark plug. But I bet you it only does this intermittently as there is no constant firing on #4 cylinder. I recommend do the compression test on #4 again just to make sure. Do this first before the paper test.

 

[kcantlon]

I re-checked the compression and got ~125psi on cylinder #4. Unable to do the wet paper test tonight since I am working alone.

I think you're onto something with the water intrusion / steam clean theory.

Should I pull the head and check the gasket and replace? Or maybe the exhaust manifold cover?

I have a friend bringing me a bore scope tomorrow so I can inspect the reeds without having to disassemble anything.

Thanks,
Kyle

 

[Jiggz]

I'm not sure when did you do the compression test. Was it when the engine was cold or at least warm. Just to be accurate, how about doing the compression test with the engine hot? I mean ran the motor for about 5~10 minutes on muffs. Shut it down and quickly dismount all plugs, activate the kill switch to make sure it doesn't start. Plug in the compression gauge and do a compression test on #4. I'm thinking the water intrusion doesn't happen until the engine is actually hot.

Since compression gauges are different from each other due to non-calibration. You also need to take compression of #1 and #2 for reference. ~125 PSI for #4 may sound great and normal but not if #1 and #2 reads 150 PSI on the same compression gauge. In short, a 10% difference between cylinder compression reading is something to be concerned about.

 

[jerryjerry05]

IF??? you had water in the cylinder you'd see it on the plug.
​Outboard Ignition .com has specs on the stator.
They post their specs and OEM specs as well.
IF?? you changed packs around and the readings from the trigger are as you stated??
Then the only thing left is the stator????
You do have DVA or Peak Reading meter?

This is your findings:
Stator resistance readings: (OEM Spec says = 680 - 800 ohms)
#1 to #2 = 1178 ohms (High)
#3 to #4 = 744 ohms (in spec)

​Sounds like the stator is bad??

 

[kcantlon]

I have been checking the compression on a cold engine. ALL four cylinders are giving me the same compression reading of right around 120-125psi. It's just a cheap tester from Harbor Freight.

Jerry, I am starting to shy away from this being an electrical issue. I switched, stator, CDM's, and coils with no change. Also the stator windings are now testing right in spec after rechecking them. That initial high reading was likely false.

I think I'm going to pull the cylinder head and inspect.

Would any of you think a bad exhaust manifold cover gasket could result in water intrusion of the combustion chamber?

Thanks,
Kyle

 

[Jiggz]

Bad gasket on either the exhaust manifold or head will cause water intrusion. If the compression on all cylinders is within 10% of each other, the most likely cause will be in the exhaust manifold. I am very hesitant in recommending opening the exhaust gasket as it is very difficult and painful not in the physical or technical sense but because of the consequences.

Being subject to heat and water, 90% of the time you'll have at least one or two broken bolts. And dealing with one in a thin aluminum block is really very painful and hard. Although there are situations when you do not have a choice but to do so.

Instead, use some water detecting paste on #4 cylinder first. Put some on #4 plug's face and disconnect its plug wire. Run the motor for about two minutes, shut it down and check. If water is present then start with the head gasket removal first. Do a post analysis and post pic of the gasket, and both mating surfaces of the head. If there is no sign of water intrusion on the head gasket, then you have no choice but to open the exhaust manifold.

Make sure you do a critical analysis of the cylinder also especially the exhaust ports area. Any sign of rusting is a sure sign water is coming in from the exhaust ports.

 

[kcantlon]

Just wanted to post a quick update about this.

I have acquired the water finding paste, new head and manifold gaskets, and a small bore camera.

I will be working on the motor first thing tomorrow morning and can hopefully report some good results in the PM.

I plan to:
1. Start with the water finding paste and hopefully get some usable results
2. Do a 1-4 compression check on a hot engine (Trying to see compression differences at temp)
3. Send the bore camera down the intake to inspect the reeds.
4. Start taking stuff apart.... I pray its the head gasket.

Sound like a good plan? Stay tuned!

Thanks,
Kyle