Coil pack testing question

I know this coil pack isn't off a car, it is off a Johnson outboard, but
thought maybe some of you knowledgeable folks might know how to test it.

It is for my sister-in-law's boat that my wife and I get to borrow so I
am trying to repair it for her.

The engine is a 2002 9.9 hp 4 stroke Johnson, Model J10TE4ST, with a two
cylinder coil pack. I believe the Johnson and Evinrude engine has the
same coil.

It will start and idle OK, but has no throttle response when the rpm
come up.

This coil only appears to put out one spark on one side, the top
cylinder. The bottom cylinder doesn't fire and the plug is wet with
gas. I put in new plugs and not a mark on it when the top one showed
clear heat marks. I swapped the plugs, same deal. The coil wires are
solid core and both of them and their 10K spark plug caps test OK with
my multimeter.

I have looked with google and can't seem to locate any resistance type
of tests for this kind of coil.

If anyone has any specs for it, I would sure appreciate them so I can
troubleshoot this engine a bit more.

The coil runs $130.00 and the brain box or module to run the coil costs
about $600.00.

Thanks,

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

| This coil only appears to put out one spark on one side, the top
| cylinder. The bottom cylinder doesn't fire and the plug is wet with
| gas. I put in new plugs and not a mark on it when the top one showed
| clear heat marks. I swapped the plugs, same deal. The coil wires are
| solid core and both of them and their 10K spark plug caps test OK with
| my multimeter.

Dumb question...

Have you swapped the wires between the two plugs to make sure that's not
causing the "no spark"?

I assume that this is a single pack, so you can't swap coils around to see
if the spark moves to the other plug, eh?

Calab wrote:
> | This coil only appears to put out one spark on one side, the top
> | cylinder. The bottom cylinder doesn't fire and the plug is wet with
> | gas. I put in new plugs and not a mark on it when the top one showed
> | clear heat marks. I swapped the plugs, same deal. The coil wires are
> | solid core and both of them and their 10K spark plug caps test OK with
> | my multimeter.
>
> Dumb question...
>
> Have you swapped the wires between the two plugs to make sure that's not
> causing the "no spark"?
>
> I assume that this is a single pack, so you can't swap coils around to see
> if the spark moves to the other plug, eh?
>
>

Yes, the wires are stranded solid copper which very seldom fails. The
10K resistor caps test out OK also.

It is a single coil pack.

I also tried running it with the coil pack in the air in case it had
'tunneled' a ground. That made no difference.

Mike

Mike Romain wrote:
> Calab wrote:
>>> This coil only appears to put out one spark on one side, the top
>>> cylinder. The bottom cylinder doesn't fire and the plug is wet with
>>> gas. I put in new plugs and not a mark on it when the top one
>>> showed clear heat marks. I swapped the plugs, same deal. The coil
>>> wires are solid core and both of them and their 10K spark plug caps
>>> test OK with my multimeter.
>>
>> Dumb question...
>>
>> Have you swapped the wires between the two plugs to make sure that's
>> not causing the "no spark"?
>>
>> I assume that this is a single pack, so you can't swap coils around
>> to see if the spark moves to the other plug, eh?
>>
>>
>
> Yes, the wires are stranded solid copper which very seldom fails. The
> 10K resistor caps test out OK also.
>
> It is a single coil pack.
>
> I also tried running it with the coil pack in the air in case it had
> 'tunneled' a ground. That made no difference.
>
> Mike

Time for a compression test.

i had a boat like that some years ago 105 chrysler. It would start and
idle nicely but it would not accelerate. I finally put it in an
auction.

W. Stief wrote:
> Mike Romain wrote:
>> Calab wrote:
>>>> This coil only appears to put out one spark on one side, the top
>>>> cylinder. The bottom cylinder doesn't fire and the plug is wet with
>>>> gas. I put in new plugs and not a mark on it when the top one
>>>> showed clear heat marks. I swapped the plugs, same deal. The coil
>>>> wires are solid core and both of them and their 10K spark plug caps
>>>> test OK with my multimeter.
>>> Dumb question...
>>>
>>> Have you swapped the wires between the two plugs to make sure that's
>>> not causing the "no spark"?
>>>
>>> I assume that this is a single pack, so you can't swap coils around
>>> to see if the spark moves to the other plug, eh?
>>>
>>>
>> Yes, the wires are stranded solid copper which very seldom fails. The
>> 10K resistor caps test out OK also.
>>
>> It is a single coil pack.
>>
>> I also tried running it with the coil pack in the air in case it had
>> 'tunneled' a ground. That made no difference.
>>
>> Mike
>
> Time for a compression test.
>
>

Unfortunately I wasn't expecting to work on engines so I didn't have my
tool kit with me for spark and compression tests.

The engine doesn't have a lot of hours on it. It wasn't blowing any
smoke at all and the oil was perfectly clear so I really hope is isn't a
blown cylinder. That would be kinda odd on a 4 stroke wouldn't it?

Mike

Mike Romain wrote:
>
> W. Stief wrote:
> > Mike Romain wrote:
> >> Calab wrote:
> >>>> This coil only appears to put out one spark on one side, the top
> >>>> cylinder. The bottom cylinder doesn't fire and the plug is wet with
> >>>> gas. I put in new plugs and not a mark on it when the top one
> >>>> showed clear heat marks. I swapped the plugs, same deal. The coil
> >>>> wires are solid core and both of them and their 10K spark plug caps
> >>>> test OK with my multimeter.
> >>> Dumb question...
> >>>
> >>> Have you swapped the wires between the two plugs to make sure that's
> >>> not causing the "no spark"?
> >>>
> >>> I assume that this is a single pack, so you can't swap coils around
> >>> to see if the spark moves to the other plug, eh?
> >>>
> >>>
> >> Yes, the wires are stranded solid copper which very seldom fails. The
> >> 10K resistor caps test out OK also.
> >>
> >> It is a single coil pack.
> >>
> >> I also tried running it with the coil pack in the air in case it had
> >> 'tunneled' a ground. That made no difference.
> >>
> >> Mike
> >
> > Time for a compression test.
> >
> >
>
> Unfortunately I wasn't expecting to work on engines so I didn't have my
> tool kit with me for spark and compression tests.
>
> The engine doesn't have a lot of hours on it. It wasn't blowing any
> smoke at all and the oil was perfectly clear so I really hope is isn't a
> blown cylinder. That would be kinda odd on a 4 stroke wouldn't it?
>
> Mike

If swapping the leads between plugs moves the no-spark to the other one,
that should certainly eliminate any possible cylinder problem. I'm
presuming this is the "waste spark" setup where both plugs are fired at
the same time, with one wasted on the cylinder on it's exhaust stroke.

lugnut wrote:
> On Thu, 17 Jul 2008 10:00:30 -0400, Mike Romain
> > wrote:
>
>> W. Stief wrote:
>>> Mike Romain wrote:
>>>> Calab wrote:
>>>>>> This coil only appears to put out one spark on one side, the top
>>>>>> cylinder. The bottom cylinder doesn't fire and the plug is wet with
>>>>>> gas. I put in new plugs and not a mark on it when the top one
>>>>>> showed clear heat marks. I swapped the plugs, same deal. The coil
>>>>>> wires are solid core and both of them and their 10K spark plug caps
>>>>>> test OK with my multimeter.
>>>>> Dumb question...
>>>>>
>>>>> Have you swapped the wires between the two plugs to make sure that's
>>>>> not causing the "no spark"?
>>>>>
>>>>> I assume that this is a single pack, so you can't swap coils around
>>>>> to see if the spark moves to the other plug, eh?
>>>>>
>>>>>
>>>> Yes, the wires are stranded solid copper which very seldom fails. The
>>>> 10K resistor caps test out OK also.
>>>>
>>>> It is a single coil pack.
>>>>
>>>> I also tried running it with the coil pack in the air in case it had
>>>> 'tunneled' a ground. That made no difference.
>>>>
>>>> Mike
>>> Time for a compression test.
>>>
>>>
>> Unfortunately I wasn't expecting to work on engines so I didn't have my
>> tool kit with me for spark and compression tests.
>>
>> The engine doesn't have a lot of hours on it. It wasn't blowing any
>> smoke at all and the oil was perfectly clear so I really hope is isn't a
>> blown cylinder. That would be kinda odd on a 4 stroke wouldn't it?
>>
>> Mike
>
>
> If it is a waste spark system and you swap the wires between
> cylinders and it still runs the same, that would indicate
> either a bad plug or a cylinder compression problem if you
> know it is getting fuel. Swapping the plugs would isolate
> the plug problem if that is the case.
>
> Lugnut

I just found out my meter was going dead so the readings went all over
the board which tosses out most of my previous assumptions..

I got a new battery in it now and the meter readings are as follows at
room temperature.

'Good' cylinder spark plug "10K" cap tests at 8.7K ohms.

'Bad' cylinder spark plug "10K" cap reads 9.7K ohms.

Primary between the two input wires, 9.4 ohms.

Reading between coil posts, 8.2K ohms.

Reading between 'either' coil post and the ground wire is infinity at my
meters 2M ohm setting.

Reading between either coil post and the positive wire is infinity also.

Unfortunately the boat is 3 hours away.

Mike

Mike Romain wrote:
>
> lugnut wrote:
> > On Thu, 17 Jul 2008 10:00:30 -0400, Mike Romain
> > > wrote:
> >
> >> W. Stief wrote:
> >>> Mike Romain wrote:
> >>>> Calab wrote:
> >>>>>> This coil only appears to put out one spark on one side, the top
> >>>>>> cylinder. The bottom cylinder doesn't fire and the plug is wet with
> >>>>>> gas. I put in new plugs and not a mark on it when the top one
> >>>>>> showed clear heat marks. I swapped the plugs, same deal. The coil
> >>>>>> wires are solid core and both of them and their 10K spark plug caps
> >>>>>> test OK with my multimeter.
> >>>>> Dumb question...
> >>>>>
> >>>>> Have you swapped the wires between the two plugs to make sure that's
> >>>>> not causing the "no spark"?
> >>>>>
> >>>>> I assume that this is a single pack, so you can't swap coils around
> >>>>> to see if the spark moves to the other plug, eh?
> >>>>>
> >>>>>
> >>>> Yes, the wires are stranded solid copper which very seldom fails. The
> >>>> 10K resistor caps test out OK also.
> >>>>
> >>>> It is a single coil pack.
> >>>>
> >>>> I also tried running it with the coil pack in the air in case it had
> >>>> 'tunneled' a ground. That made no difference.
> >>>>
> >>>> Mike
> >>> Time for a compression test.
> >>>
> >>>
> >> Unfortunately I wasn't expecting to work on engines so I didn't have my
> >> tool kit with me for spark and compression tests.
> >>
> >> The engine doesn't have a lot of hours on it. It wasn't blowing any
> >> smoke at all and the oil was perfectly clear so I really hope is isn't a
> >> blown cylinder. That would be kinda odd on a 4 stroke wouldn't it?
> >>
> >> Mike
> >
> >
> > If it is a waste spark system and you swap the wires between
> > cylinders and it still runs the same, that would indicate
> > either a bad plug or a cylinder compression problem if you
> > know it is getting fuel. Swapping the plugs would isolate
> > the plug problem if that is the case.
> >
> > Lugnut
>
> I just found out my meter was going dead so the readings went all over
> the board which tosses out most of my previous assumptions..
>
> I got a new battery in it now and the meter readings are as follows at
> room temperature.
>
> 'Good' cylinder spark plug "10K" cap tests at 8.7K ohms.
>
> 'Bad' cylinder spark plug "10K" cap reads 9.7K ohms.
>
> Primary between the two input wires, 9.4 ohms.
>
> Reading between coil posts, 8.2K ohms.
>
> Reading between 'either' coil post and the ground wire is infinity at my
> meters 2M ohm setting.
>
> Reading between either coil post and the positive wire is infinity also.
>
> Unfortunately the boat is 3 hours away.
>
> Mike

Ok, it sounds like the plugs operate in series, i.e. the spark voltage
goes out one coil post, through one spark plug to the engine block and
back through the other spark plug and back to the other coil post. If
this is the case, since you don't see any apparent leak to ground in the
coil, your problem seems to be outside the coil pack. Sounds like you
may well have a problem with the engine itself.

Mike Romain wrote:
> lugnut wrote:
>> On Thu, 17 Jul 2008 10:00:30 -0400, Mike Romain
>> > wrote:
>>
>>> W. Stief wrote:
>>>> Mike Romain wrote:
>>>>> Calab wrote:
>>>>>>> This coil only appears to put out one spark on one side, the top
>>>>>>> cylinder. The bottom cylinder doesn't fire and the plug is wet with
>>>>>>> gas. I put in new plugs and not a mark on it when the top one
>>>>>>> showed clear heat marks. I swapped the plugs, same deal. The coil
>>>>>>> wires are solid core and both of them and their 10K spark plug caps
>>>>>>> test OK with my multimeter.
>>>>>> Dumb question...
>>>>>>
>>>>>> Have you swapped the wires between the two plugs to make sure that's
>>>>>> not causing the "no spark"?
>>>>>>
>>>>>> I assume that this is a single pack, so you can't swap coils around
>>>>>> to see if the spark moves to the other plug, eh?
>>>>>>
>>>>>>
>>>>> Yes, the wires are stranded solid copper which very seldom fails. The
>>>>> 10K resistor caps test out OK also.
>>>>>
>>>>> It is a single coil pack.
>>>>>
>>>>> I also tried running it with the coil pack in the air in case it had
>>>>> 'tunneled' a ground. That made no difference.
>>>>>
>>>>> Mike
>>>> Time for a compression test.
>>>>
>>>>
>>> Unfortunately I wasn't expecting to work on engines so I didn't have my
>>> tool kit with me for spark and compression tests.
>>>
>>> The engine doesn't have a lot of hours on it. It wasn't blowing any
>>> smoke at all and the oil was perfectly clear so I really hope is isn't a
>>> blown cylinder. That would be kinda odd on a 4 stroke wouldn't it?
>>>
>>> Mike
>>
>> If it is a waste spark system and you swap the wires between
>> cylinders and it still runs the same, that would indicate
>> either a bad plug or a cylinder compression problem if you
>> know it is getting fuel. Swapping the plugs would isolate
>> the plug problem if that is the case.
>>
>> Lugnut
>
> I just found out my meter was going dead so the readings went all over
> the board which tosses out most of my previous assumptions..
>
> I got a new battery in it now and the meter readings are as follows at
> room temperature.
>
> 'Good' cylinder spark plug "10K" cap tests at 8.7K ohms.
>
> 'Bad' cylinder spark plug "10K" cap reads 9.7K ohms.
>
> Primary between the two input wires, 9.4 ohms.
>
> Reading between coil posts, 8.2K ohms.
>
> Reading between 'either' coil post and the ground wire is infinity at my
> meters 2M ohm setting.
>
> Reading between either coil post and the positive wire is infinity also.
>
> Unfortunately the boat is 3 hours away.
>
> Mike

It could be the coil pack . IMO, they really cannot be tested much with
an ohmmeter.
Its possible some of the internal insulation has been blasted off the
wires and it
shorts out at RF frequencies and high voltage.
What I have done in the past with automotive waste spark coils is to
heat them
in the oven for an hour at 150-200 degrees F (not C !!!) and then try
the ohmmeter again.
Iif you can find out the low side operating voltage (possibly 7.5 v),
hook it to a
reasonable appropriate voltage on one side and run the other wire
over a rasp or something to simulate make / break. Make spark gaps between
both high sides and ground. Do this while the coil is hot at 150F or so.