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).

Have you made sure the deadman lanyard is connected?
Jim
"TSC" wrote in message
...
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).

Thanks for the suggestion.

How do I confirm that one even exists?

It is a 1987 19 foot Rinker cuddy.

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).



Do you have 12 volts at the coil while cranking?

How did you set the points gap?

Rob

"TSC" wrote in message
...
Thanks for the suggestion.

How do I confirm that one even exists?

It is a 1987 19 foot Rinker cuddy.


Pull the main wiring harness plug and clean, use some di-eclectic grease.
That one plug will cause a Merc to either quit or not start. Also, check the
ground from the battery to the engine. Good luck, Dan

"TSC" wrote in message
...
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

Get yourself a repair manual (will have the wiring schematics) and a good
voltmeter. Make sure you have power to everything then start disconnecting
everything that taps power off the coil. My boat would start to miss and
then die. Turned out the tach was shorted and grounding out the coil. With
a good volt meter you can work your way though the electrical system. You
may also consider converting from points to an electronic system. The kits
are less then $100 and will take you about an hour (summit racing and Jegs
have the marine kits). They give you a new plate that takes place of the
points/condenser plate in the distributor. We saw a world of difference
starting and much less gas usage. In fact we were able to stretch a 75 gal
fuel tank to last the whole season last year.

good luck,
mark

I think you just did confirm that it doesn't exist on your boat. There would
be a cord that must be snapped into a receptacle on the dash or shift
module, and the other end is attached to your wrist. Another odd thing that
could short out your ignition is a shorted tachometer. You could prove that
out by removing the gray tach lead from the coil. When you changed the
points there should have been a little piece of paper in the kit. That is
used to clean off any film that might be on the contact points. Use a dwell
meter to set the point gap and you probably won't need to set the timing.
Another simple trick is to run a jumper from + on the battery to + on the
coil. If it starts you need to trace back toward the ignition switch, which
could also be the problem. In order to get to this problem, you need to
abandon this easter egg hunt and do some systematic troubleshooting. Finding
out weather there is 12V on the coil is a good starting point.
I suggest that you keep all of the tips you have received in this thread.
They might prove useful when you start troubleshooting.
Jim
"TSC" wrote in message
...
Thanks for the suggestion.

How do I confirm that one even exists?

It is a 1987 19 foot Rinker cuddy.

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.

TSC wrote:
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?

YES.

Do you have 12 volts at the coil (+) while cranking?

How did you set the points gap?


Note that I checked for spark at the points,

This is not how you check for spark. There should be no spark at the
points if the condensor is working right.

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 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