1974 Evinrude 85hp Starflite no spark: troubleshooting help

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Atoyot1031

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I purchased a 1974 Evinrude Starflite 85hp V4 (model 85493) for my son & I's 16' aluminum fishing boat.

After mounting the motor, we cleaned carbs, adjusted linkaged/cables, and fired the engine. It ran well, but didn't have water coming out of the telltale. So we removed the lower unit, rebuild the water pump, flushed out the coolant lines and re-assembled.

When we went to start it following that work, it would not start. We checked for spark. Weak spark on #3, no spark at all on #1,2,4.

I purchased a Factory Service Manual for the motor. The FSM conducts many of the troubleshooting tests using an S-80 or M80 neon test light. I believe these are obsolete. I have multimeters (and know how to use them). I also build a peak voltage adapter for a multimeter. Testing what I could from the FSM & what I've found online, here's my results this far:

1. Brand new spark plugs.
2. No spark on #1,2,4 cylinders. Spark on #3 cylinder.
3. Disconnect black/yellow from power pack- still no spark.
4. Disconnect remote entirely and jump starter- still no spark.
5. Check ground connections for power pack- Good.
6. Checking charge coil- Resistance test power pack leads brown to brown/yellow (terminals 7 to 8)- 658ohms (manual says shod read 910 +/- 75 ohms) FAIL? Manual doesn't state what to do if out of spec.
7. Sensor coil test- Resistance test power pack leads (after disconnecting) terminals 2 to 4 (sensor lead 2 & 4) and 9 to 12 (sensor lead 1 & 3)- 7.8 to 8.0 ohms (manual says should read 8.5 +/- 2.0 ohms).
8. Test peak voltage of stator between brown & brown/yellow while cranking. Read 256VDC peak.

Any help is appreciated. Or if someone can point me in the direction of a troubleshooting matrix that utilizes a modern multimeter and peak voltage adapter. That would be great too.

Thanks in advance!
Nick
 
dingbat

dingbat

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Atoyot1031 said:
6. Checking charge coil- Resistance test power pack leads brown to brown/yellow (terminals 7 to 8)- 658ohms (manual says shod read 910 +/- 75 ohms) FAIL? Manual doesn't state what to do if out of spec.
Click to expand...
Typically you replace failed component and move on otherwise downstream components will not perform as required
Atoyot1031 said:
8. Test peak voltage of stator between brown & brown/yellow while cranking. Read 256VDC peak.
Click to expand...
I believe that should be AC voltage
 
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racerone

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Some will argue.----I would charge the battery.----Then have battery load tested ( even if new ) last week.-----Then take starter apart for inspection .----Test ohms on armature.----No money spent on these tests !
 
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saltchuckmatt

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racerone said:
Some will argue.----I would charge the battery.----Then have battery load tested ( even if new ) last week.-----Then take starter apart for inspection .----Test ohms on armature.----No money spent on these tests !
Click to expand...
Pretty sure his starter is working, just his motor won't run.

Needs instructions on how to test his ignition components with newer style testing equipment.
 
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racerone

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The man says is motor is now NOT STARTING.-----Easy to follow steps in post # 3 and no money spent.
 
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Atoyot1031

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racerone said:
Some will argue.----I would charge the battery.----Then have battery load tested ( even if new ) last week.-----Then take starter apart for inspection .----Test ohms on armature.----No money spent on these tests !
Click to expand...
FSM doe state that the starter needs to be able to turn the motor over at least achieving 300 RPM. So I did run it with a running truck battery hooked up while ensuring the voltage remained 12+ while cranking. Good idea, but starter and battery appear to be working properly. Thx!
 
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Atoyot1031

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dingbat said:
Typically you replace failed component and move on otherwise downstream components will not perform as required

I believe that should be AC voltage
Click to expand...
Agree to typically replace the failed component. However, on this particular test, the FSM doesn't state what to replace, where as in the very next step (testing charge coil- leads for shorts) it explicitly states that a "zero reading indicates leads or charge coil- is shorted to ground and should be replaced.". Oddsince verbage in troubleshooting guides is typically very deliberate.

Regard the voltage, FSM states under "Theory of Operation" that the flywheel magnets passing the charge coils generate 300VAC. That power goes into the Power Pack where it is changed (converted) from AC to DC and store in a capacitor.

Thanks for the insights!
 
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saltchuckmatt

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Joined
Jul 19, 2019
Messages
2,857
Atoyot1031 said:
Agree to typically replace the failed component. However, on this particular test, the FSM doesn't state what to replace, where as in the very next step (testing charge coil- leads for shorts) it explicitly states that a "zero reading indicates leads or charge coil- is shorted to ground and should be replaced.". Oddsince verbage in troubleshooting guides is typically very deliberate.

Regard the voltage, FSM states under "Theory of Operation" that the flywheel magnets passing the charge coils generate 300VAC. That power goes into the Power Pack where it is changed (converted) from AC to DC and store in a capacitor.

Thanks for the insights!
Click to expand...
Did you find this? Maybe it will help.
 

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