1980 Ski Supreme no spark

I tried a search and found some answers but I'd like to get input based off of my question. So, this is my dads boat and it has been sitting for..maybe 7 or 8 years? Oil and gas were replaced when I took it out of storage and the battery and plugs were replaced before it was stored. Before it was stored it ran great. it is the Ford 351 engine

Now, Everything cranks, getting 12V at the starter all the way to the reastat(?) from there, the voltage drops to about 6V going up into and out of the coil but seems to disappear when it gets to the distributor. I pulled the plugs and saw no spark.

First, is the voltage supposed to drop like that from 12 to 6v?
Second, looks like the points are not entirely good. I did file them so shouldn't i be expecting something to happen? everything else in the distributor is new..well..new when it was stored.

Any help is appreciated,

Thank you

The voltage is about right for a resistor wire going to the points. Did you clean off the points good, you could probably use emery cloth, or a finger nail board, but clean them off with alcohol afterward so they're not dirty, or greasy. Clean the rotor, & distributor cap the same way, then make sure the points are opening, closing, and check for spark as the rotor is turning, while you crank the ignition with the Dist. cap off.

A generic setting for the points is about .017" gap. Do this, then get back to us.

I did everything you asked. And still nothing. Points are opening and closing, they are clean and within spec. But there is no spark.

I did a volt test inside the distributor on the brown wire heading to the points and while cranking it's drawing about -9v. Not cranking it is drawing 0v

Kyle, from what you describe, you have what's called a kettering system..... I.E., contact points ignition system.

Depending on the type of ignition coil, you'll have either a full 12 vdc or a resisted voltage leading to the coil + side.

The contact points take the primary side of the coil to Negative when closed. This creates coil "saturation".
The condensor stores this energy momentarily.

When the contacts break, the primary side field collapses, causing the secondary side to produce high voltage output for one spark event.
You can think of this as a one-cycle AC transformer...... so to speak.

The distributor rotor's job is to distribute the spark to the correct spark plug wire post contact or pole within the cap.
This is refered to as the "firing order".


Your distributor rotates 360* for all 8 cylinders to recieve one spark event per cylinder during the completion of 4 engine cycles (i.e., two full crankshaft revolutions).

360* divided by 8 cylinders = 45* per cylinder.
Of this 45*, a portion of this is the dwell angle (i.e., coil saturation duration).
The dwell angle will be approx 30*-31* of the 45* (see your OEM specs).

The coil must be correct and working.
The coil voltage must be correct for the coil.
The contact points must be clean and must make good contact to negative.
Points must be set/adjusted for the correct dwell angle.
The condensor must also be good.

Now.... there's a bit more to this.
During cranking, voltage to the coil drops due to the heavy demand of the starter motor.
This drop in voltage may cause a weak or even no spark.
Your system should have a "start-by-pass" circuit that provides full voltage to the coil while cranking.

One type of start-by-pass circuit uses an I or R terminal on the starter motor solenoid.
Another type may use a small relay.

Go down these items one at a time, and you'll find the issue.


When a good ignition coil + side is taken to Negative by the contacts...... and with a good condensor in the loop...... and when the contacts break..... you should be able to see a good blue or whitish blue spark that makes an audible snap.

A yellowish spark is a weak spark.


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