I hear ya, Rob, but I don't think I stated things clearly. I meant to say
that I pulled the coil wire and held it near a ground. I ALSO looked for
spark at the spark plug wire. I did NOT do both tests at the same time,
although my statement makes it look like I did! I realize that there will be
no spark at the plug wires if the coil wire is disconnected!

I will check for 12 volts. I would have done so tonight, but my multimeter
had a dead battery. Would I hold the probes to the pos and neg on the coil,
or am I better off using another ground point?

Back to the ballast resistor, I know what a ballast resistor from an old
Dodge looks like, and I know what it does, but I cannot find one in the
wiring diagram or on the boat.



by pulling the coil wire and
holding it near a ground, and by putting a spare spark plug into a plug
wire.

That is spark at the secondary side of the coil. You will get no spark at
any plug wire with the coil wire pulled.

Trust me... there is no spark.

You really need to check that you have 12 volts at the coil while
cranking, 9-10 volts in the "run" position.

You will get no spark ever if you don't get this 12 volts cranking first,
and have the points set to open to the specified gap twice every engine
revolution.

Rob

TSC wrote:

I hear ya, Rob, but I don't think I stated things clearly. I meant to say
that I pulled the coil wire and held it near a ground. I ALSO looked for
spark at the spark plug wire. I did NOT do both tests at the same time,
although my statement makes it look like I did! I realize that there will be
no spark at the plug wires if the coil wire is disconnected!

I will check for 12 volts. I would have done so tonight, but my multimeter
had a dead battery. Would I hold the probes to the pos and neg on the coil,
or am I better off using another ground point?

Back to the ballast resistor, I know what a ballast resistor from an old
Dodge looks like, and I know what it does, but I cannot find one in the
wiring diagram or on the boat.



You are SOL w/o checking coil voltage, (+) to ground, not the switched
(-) of the coil. You can use a 12 volt test probe or even a 1156 or 904
12v bulb to confirm there is power to the coil if your meter is DOA.

There really is no sense in checking for spark distribution or
generation until you get your ignition primary side confirmed working.

I still don't get the part about checking the spark at the points...

Rob

TSC wrote:

I hear ya, Rob, but I don't think I stated things clearly...

.... Back to the ballast resistor, I know what a ballast resistor from an
old
Dodge looks like, and I know what it does, but I cannot find one in the
wiring diagram or on the boat...

It could be inside the harness, or it could be a section of resistance
wire, or a ceramic block type between the terminal block(solenoid area)
& the coil.

Rob

You really need to check that you have 12 volts at the coil while
cranking, 9-10 volts in the "run" position.

You will get no spark ever if you don't get this 12 volts cranking first,
and have the points set to open to the specified gap twice every engine
revolution.

Rob

The fellow really needs to pay attention to your statements and begin
systematic troubleshooting of the problem.
Jim.

It is not a matter of not paying attention. There are two objectives here.

The parts that I am removing and replacing are not a complete waste of time
or money. We are talking about 20 year old ignition components that, even if
they work, I am much more comfortable replacing for the price that they
cost.

So, despite how it appears, this is not a "replace everything and hope it
works" approach. As I checked each of replaced parts I saw things that I did
not like. Such as lots of carbon on the contacts inside the distributor cap,
cracks in the plug wires, etc etc. These are parts that have the potential
to leave you stranded out on the water and warranted replacement. It is not
so much that I really expected any individual part to miraculously solve my
problem.

When I read back through this thread, I can completely understand why you
guys are frustrated that I have not checked for 12 volts yet. Trust me, on
the way tonight I will buy a GOOD multimeter instead of the piece of junk I
use for pinball machine repair and I will follow your advice to the letter.

I really do appreciate the advice.

Thanks
Tim







"Jim" wrote in message
link.net...
You really need to check that you have 12 volts at the coil while
cranking, 9-10 volts in the "run" position.

You will get no spark ever if you don't get this 12 volts cranking first,
and have the points set to open to the specified gap twice every engine
revolution.

Rob

The fellow really needs to pay attention to your statements and begin
systematic troubleshooting of the problem.
Jim.

"TSC" wrote in message
...
I have the Siloc book. I went through the troubleshooting, and I have no
spark anywhere.

Curiously, the wiring diagrams in the book do not show an external ballast
resistor. I have following the wires from the coil and I cannot locate one
either.

The original coil (which I replaced) says the only use it with an external
resistor. I made sure the new coil was for use with an external resistor.

Any clues as to where the resisitor would be?

Would a faulty resistor allow it to crank, but show no spark?

Note that I checked for spark at the points, by pulling the coil wire and
holding it near a ground, and by putting a spare spark plug into a plug
wire.

Trust me... there is no spark.

Ok let me ask you this... Key on do you see 12v on the positive (+)
terminal of the coil with the key on?

If NO
then hooking up a wire with gator clips from the positive (+) battery
terminal to the positive (+) side of the coil. See if it will start if so
pull the clip off if it dies then you have a problem with the external
resistor. In this case just ignore it, go get a internal resistor coil and
run a wire directly from the ignition switch to the coil. Don't use the
external resistor coil on 12 volts it will overheat. You can in the future
use this new 12volt wire to run the electronic pickup that you will
eventually install in place of the points...... I suspect this is not your
problem as it will not start even when the starter is running.

If YES
there is power to coil with key on then I would unhook everything from
the negative (-) terminal of the coil except for the points (should be a
single wire running from points/condenser to coil). See if it starts and
runs. If so tach is dead or short in shift interrupt system. The way the
coil works is such... the coil charges when positive power is on and the
coil is grounding though the points. When the lobe in the distributor gets
to the proper position it opens the points breaking the ground to the coil
and the power stops flowing in the secondary circuit in the coil. When this
happens it creates a magnetic pulse in the coil that is picked up by the
primary circuit and is send out of the coil as a high voltage "jolt" that is
then sent to the plugs. If the ground circuit is always grounded no spark
or if the circuit does not close (no ground) no spark. I bet this is where
your problem is in the system.

During cranking the starting system will feed a full 12volts to the coil
then when the starter is off it feeds ~10volts to the coil through the
resistor circuit (voltage will depend on the resistor but should be between
7-10volts).

From what I have read in your posts I bet you have a ground issue.

I went though something similar last year with my OMC.

Let us know how you make out.

good luck,
mark

Thanks r_d,

I will follow your directions tomorrow night and report back.

-Tim



"r_d" wrote in message
. com...

"TSC" wrote in message
...
I have the Siloc book. I went through the troubleshooting, and I have no
spark anywhere.

Curiously, the wiring diagrams in the book do not show an external
ballast resistor. I have following the wires from the coil and I cannot
locate one either.

The original coil (which I replaced) says the only use it with an
external resistor. I made sure the new coil was for use with an external
resistor.

Any clues as to where the resisitor would be?

Would a faulty resistor allow it to crank, but show no spark?

Note that I checked for spark at the points, by pulling the coil wire and
holding it near a ground, and by putting a spare spark plug into a plug
wire.

Trust me... there is no spark.

Ok let me ask you this... Key on do you see 12v on the positive (+)
terminal of the coil with the key on?

If NO
then hooking up a wire with gator clips from the positive (+) battery
terminal to the positive (+) side of the coil. See if it will start if so
pull the clip off if it dies then you have a problem with the external
resistor. In this case just ignore it, go get a internal resistor coil
and run a wire directly from the ignition switch to the coil. Don't use
the external resistor coil on 12 volts it will overheat. You can in the
future use this new 12volt wire to run the electronic pickup that you will
eventually install in place of the points...... I suspect this is not
your problem as it will not start even when the starter is running.

If YES
there is power to coil with key on then I would unhook everything from
the negative (-) terminal of the coil except for the points (should be a
single wire running from points/condenser to coil). See if it starts and
runs. If so tach is dead or short in shift interrupt system. The way the
coil works is such... the coil charges when positive power is on and the
coil is grounding though the points. When the lobe in the distributor
gets to the proper position it opens the points breaking the ground to the
coil and the power stops flowing in the secondary circuit in the coil.
When this happens it creates a magnetic pulse in the coil that is picked
up by the primary circuit and is send out of the coil as a high voltage
"jolt" that is then sent to the plugs. If the ground circuit is always
grounded no spark or if the circuit does not close (no ground) no spark.
I bet this is where your problem is in the system.

During cranking the starting system will feed a full 12volts to the coil
then when the starter is off it feeds ~10volts to the coil through the
resistor circuit (voltage will depend on the resistor but should be
between 7-10volts).

From what I have read in your posts I bet you have a ground issue.

I went though something similar last year with my OMC.

Let us know how you make out.

good luck,
mark

I do NOT see 12 volts on the positive side of the coil with the key on. This
is using a volt meter. I tested the volt meter at the battery and got the
full 12 volts. Testing at the coil gives me nothing.

Hooking up a wire with gator clips to the positive side of the battery to
the positive side of the coil produces no change. Keeps turning over nice
and strong, but no firing whatsoever.

By the way, I *did* remove the tach wire while conducting all tests.

I changed back to my original coil and performed the tests again. No change.

I am going to have to wait for daylight to continue this saga.








Ok let me ask you this... Key on do you see 12v on the positive (+)
terminal of the coil with the key on?

If NO
then hooking up a wire with gator clips from the positive (+) battery
terminal to the positive (+) side of the coil. See if it will start if so
pull the clip off if it dies then you have a problem with the external
resistor. In this case just ignore it, go get a internal resistor coil
and run a wire directly from the ignition switch to the coil. Don't use
the external resistor coil on 12 volts it will overheat. You can in the
future use this new 12volt wire to run the electronic pickup that you will
eventually install in place of the points...... I suspect this is not
your problem as it will not start even when the starter is running.

If YES
there is power to coil with key on then I would unhook everything from
the negative (-) terminal of the coil except for the points (should be a
single wire running from points/condenser to coil). See if it starts and
runs. If so tach is dead or short in shift interrupt system. The way the
coil works is such... the coil charges when positive power is on and the
coil is grounding though the points. When the lobe in the distributor
gets to the proper position it opens the points breaking the ground to the
coil and the power stops flowing in the secondary circuit in the coil.
When this happens it creates a magnetic pulse in the coil that is picked
up by the primary circuit and is send out of the coil as a high voltage
"jolt" that is then sent to the plugs. If the ground circuit is always
grounded no spark or if the circuit does not close (no ground) no spark.
I bet this is where your problem is in the system.

During cranking the starting system will feed a full 12volts to the coil
then when the starter is off it feeds ~10volts to the coil through the
resistor circuit (voltage will depend on the resistor but should be
between 7-10volts).

From what I have read in your posts I bet you have a ground issue.

I went though something similar last year with my OMC.

Let us know how you make out.

good luck,
mark

TSC wrote:
I do NOT see 12 volts on the positive side of the coil with the key on. This
is using a volt meter.

Digital or analog?

I tested the volt meter at the battery and got the
full 12 volts. Testing at the coil gives me nothing.

The coil (+) and... What did you use for a ground(-)?

Hooking up a wire with gator clips to the positive side of the battery to
the positive side of the coil produces no change.

Do you mean that you still do not have 12 volts at the coil to ground?
What are you using for a ground on this test? There always has to be a
reference to ground or we cannot help you figure this out.

Keeps turning over nice
and strong, but no firing whatsoever.

You will get no spark ever if you don't get this 12 volts at the coil to
ground cranking first, and have the points set to open to the specified
gap twice every engine revolution.

How did you set the points gap?


By the way, I *did* remove the tach wire while conducting all tests.

You removed it from what? It should be one of two connections at the
(-) post on the coil. It won't make a lick of difference, though, if
you still do not have 12 volts at the coil(+) to ground(not coil"-")
while cranking.


I changed back to my original coil and performed the tests again. No change.

It won't make any difference which coil you use to get the 12 volts coil
(+) to ground.

I am going to have to wait for daylight to continue this saga.

Let us know!


Rob

I have had the same problem, when i cranked it cranked kina slow, i did
all you did too but it would not start. i found that i had to replace
the starter. What was happening was the starter was draging and drawing
exessive amps and hence causing the engine not to start and the
cylindars not to fire. It is worth checking:

Pull the starter, and see how much play you have when you tip it back
and forth, execive play is bad, it is an exspensive fix but worth it,
and from what you are saying sounds like the fault.

Loren


TSC wrote:
Still working on this, and there must be something I am missing.

This is a 1987 Mercruiser Stern Drive with a 3.8 Litre 165 Horsepower four
cylinder

I have replaced...

Spark Plug Wires
Spark Plugs, gapped to specs
Distributor Cap
Rotor
Condenser
Ignition Points, gapped to specs
Coil

I have checked and rechecked to confirm the parts are correct for the
application

I have drained gas tank completely and added 10 gallons of fresh gas
I have tried with starting fluid
I have looked down the carb to verify that it is getting fuel
I have verified that the in-line circuit breaker is not tripped

There is NO spark whatsoever. It just turns over forever.

I have adjusted the timing every degree for 10 degrees in each direction and
there is NO spark.

Since I have replaced everything electrical that I can think of, and there
is still no spark, what else is there to do?

It has fuel. It has air. And all the electrical parts are new.

Previous owner inisists it ran fine when parked three seasons ago
(naturally).