OX66 225 coil packs

[Parker2510_OX66]

Is there anything that would cause coil packs to go bad other than just old age?

Motor is a 02 OX66 SX225TXRA.

I ask because I found #3 coil pack to be bad. Swapped 3 and 5 to test. Replaced the bad one, which was then on #5. Motor ran fine in the tub, smooth, like a sewing machine 2 weeks ago. Hadnt ran it since. Put it in the river today and lost coil packs #1 and #3. I used a Lisle inline spark tester to determine they are bad. #2, 4 and 6 all show spark on the tester at idle. #5 does not as it is a selective cylinder motor.

I have no idea if the coil packs have been replaced by the previous 2 owners. To be safe I assume they have not. Motor has 940 hours on it.

Any help and advice is appreciated. Thank you!

[rodbolt17]

ign coil failure is so rare we don't stock them.
did you test the spark plug cap?
did you test the CDI inputs?
did you test the CDI outputs?
you realize under certain conditions 2 and 5 wont spark.

[Parker2510_OX66]

ign coil failure is so rare we don't stock them.
did you test the spark plug cap?
did you test the CDI inputs?
did you test the CDI outputs?
you realize under certain conditions 2 and 5 wont spark.

No to the top three questions. I just replaced the initial one that had no spark and now two more have gone out. I just find it odd that its the same side of the motor. Inevitably this is leading to the CDI. However, I will test the caps as they are old. Might even swap the coils from the port side to the starboard side and see if that makes a difference.



Yes, i realize 5 doesnt fire at idle and 2 doesnt fire between like 850 rpm and 2k rpm and all 6 come online after 2k rpm. selective cylinder.


thanks for the direction. I will definitely check those three things out.

[99yam40]

testing the inputs and outputs of the CDI while cranking and then when Running/idling should shine a light on where the problem is happening.

need to know if all of the components are doing what they should.

bad voltages into the cdi means something beside CDI and ignition coils have a problem.
good into CDI but bad out means something altogether different along with good out but bad out of high voltage coil.
testing saves time and money

[rodbolt17]

CDI failure is even more rare than ign coil failure. you do realize that the stator has TWO charge coils.
one for each bank.
lose one and you lost a bank.
that is why careful testing is preferred over random replacing of parts.

[Parker2510_OX66]

CDI failure is even more rare than ign coil failure. you do realize that the stator has TWO charge coils.
one for each bank.
lose one and you lost a bank.
that is why careful testing is preferred over random replacing of parts.

Fially got the boat in the yard and was able to test everything out according to the steps inthe shop manual. Charge coils are bad. When I looked under the flywheel with a flash light you could see a very burnt wire or connector.

DVA adapter and the test harnesses made it super easy.

[Parker2510_OX66]

Anyone have any idea what caused this to happen to my charge coils?

[boscoe99]

My guess would be chaffing of a wire that allowed current to flow where it is not suppose to flow and in amounts it is not supposed to flow.

[zenoahphobic]

My guess would be chaffing of a wire that allowed current to flow where it is not suppose to flow and in amounts it is not supposed to flow.

Yes nasty. That coil unlikely burnt like that from the self generated voltage; the voltage and amps may have come from up the line somewhere. Critically look at the burnt coil to see if there were wires shorting, you may cut it open to see if the windings have burnt through.

This means do not change the stator without finding the fault.

[Parker2510_OX66]

Does the CDI regulate the voltage from the Charge coils?

[rodbolt17]

no. the CDI simply rectifies the AC and stores it in a capacitor until triggered by a pulser coil.
electrical parts do fail and it is a 15 year old part.

[panasonic]

Perhaps one of those old brittle looking tye wraps fell off and the wires chafed on the flywheel..Who ever cut the ends off those tye wraps needs a Crack across the knuckles as well....pet peeve.

[Parker2510_OX66]

no. the CDI simply rectifies the AC and stores it in a capacitor until triggered by a pulser coil.
electrical parts do fail and it is a 15 year old part.

OK. Then how is it the new charge coils are peaking voltage at 150vDC cranking and 230vDC idle? Trouble shooting Steps then say if the charge coils are above spec check the pulsar coils. Which those are also above spec(peaking anywhere from 3.5-4.5vDC depending on the which wire you test), which says replace the CDI unit. With that logic it would seem the CDI is regulating the voltage coming down the line from the charge coils to the CDI. Shop manual also says to test the pulsar coils and charge coils as DC voltage. So are the charge coils making AC or DC voltage? I know the stator(lighting coil) makes 3 phase AC voltage and is rectified at the voltage regulator into DC voltage.

[Parker2510_OX66]

Perhaps one of those old brittle looking tye wraps fell off and the wires chafed on the flywheel..Who ever cut the ends off those tye wraps needs a Crack across the knuckles as well....pet peeve.

No. The wire tie was completely fried in half. The charge coils look like they were overloaded. severely overloaded.

[99yam40]

did you test the lighting coils also?
just trying to make sure what you see burnt up is charge coils.
lighting coils would make more sense to get burnt up like that and then affect the wiring maybe to the charge coils