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1984 evinrude 40 hp shuts down but getting gas

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RESDESIGNER

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Running fine - shut down like turning off switch. Waited 5 min. Started back once ran about a minute shut down for good. Carbs getting gas - seems electrical. Stator?? Power pack?? Any simple testing to isolate?
 
I started to check compression, spark, power pack, stator and the engine fired up and ran fine. When it quit last, it had fuel to carbs but was in the water and I could not verify if it was firing. I go to take it out of the water and it now runs. The day after it quit last, it would not crank (last weekend) but now it runs (this weekend). Any ideas on how to trouble shoot now? Just because if runs now I don't want to get stranded again. What electrical parts might be more likely to be affected by heat? Maybe I start with that?
 
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Voltage To Powerpack Failures
(Magneto Capacitance Discharge Systems)
(J. Reeves)

The usual cause of having those type powerpacks fail repeatedly is having a very small of voltage applied to the Black/Yellow wire (Kill Circuit) at the pack. Test as follows.
Disconnect the Black/Yellow wire at the powerpack.

Insert either a ampere meter or a volt meter set to its lowest DC voltage reading between that Black Yellow wire and ground.

With the ignition key in the OFF position, observe the meter reading. Now turn the ignition key to the ON position and again observe the meter reading.

Any reading, movement of the meter needle, even a microvolt, would indicate that battery voltage is being applied to that Black/Yellow wire. If a reading is present, remove the other end of that Black/Yellow from the raised terminal of the ignition switch.

If the reading ceases to exist when the Black/Yellow wire is removed from the ignition switch, replace the switch. If the reading continues to exist, there would be a short of some kind in either the engine or instrument wiring harness.... to determine which, simply unplug the large RED electrical plug at the engine which would eliminate the instrument cable.

Note that the black/yellow wire must not have any other wire attached to it for the following reason!

Keep in mind that any accessory that has 12 volts running to it, especially when turned on, will have voltage flowing thru it and trailering out thru its black ground wire to complete the circuit. If that accessory has it's black ground wire attached to the "M" terminal that the black/yellow wire is attached to.... you will have voltage flowing directly to the powerpack.

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First, I found the silicone filled rectifier red wire is broke in several places. I have a new one now and will install today. Could that bad wire on the rectifier shut down the motor? After I found the broke wire and disconnected he wire completely, I was able to get the engine to run (seem to run rough) but did not run it but for few seconds - was concerned I could hurt something else w/ rectifier red wire not connected. Should I continue with the trouble shooting Joe sent earlier???
 
Some boaters and mechanics swear that a faulty rectifier affects the ignition.... it's not supposed to!

Just to be on the safe side, I'd suggest you do that trouble shooting procedure just to eliminate that possibility and give you peace of mind.
 
Joe, I have 8 to 10 microvolts on the b/y wire with the ignition key on - 0 m/v with switch off. I still have 8-10 m/v showing with the b/y wire off at the switch terminal. I have same m/v showing when I unplug the red plug at engine. My question - does that show a short between red plug and pack or between red plug & switch??? The meter red lead is on the b/y at the plug that disconnects the pack (engine side of plug - not on pack side) and the plug is not connected. If short is on engine side not cable side, should I run new b/y wire and ignore old one?
 
Maybe that was to wordy - What is not clear is with power still showing with red plug disconnected, does that mean wire short on engine or cable from engine to switch?? I see it as cable from switch to engine is okay??? Anybody with an idea?
 
RESDESIGNER said:
1 - I did run the list and found I have 8 to 10 microvolts still on the motor or harness.
Click to expand...

1 - I assume that here the black/yellow wire is removed from the "M" terminal of the ignition switch and you have the red lead of a volt meter between the black/yellow wire near the switch or at the engine that is part of the engine's wiring harness but is disconnected from the powerpack? Black lead to ground. If so, a internal short exists somewhere within the wiring harnesses.
RESDESIGNER said:
2 - The switch tested fine.
Click to expand...

2 - Does this mean that the black/yellow wire is disconnected from the "M" terminal of the ignition switch, the red lead of the meter is attached to that "M" terminal with the meter's black lead attached to ground... and with the key ON or OFF no voltage exists at the "M" terminal? If so, then the switch is okay.
RESDESIGNER said:
3 - I did unplug the red plug on the engine and with the switch on, I still have 8 to 10 mv showing.
Click to expand...

3 - Is the black/yellow wire removed from the "M" terminal? What are the meter leads attached to?
RESDESIGNER said:
4 - Now I have the test meter set with the red lead on the motor side of the plug going to the pack (unplugged) and the black lead on the battery negative ground. Switch on 8-10 mv - switch off, no voltage. With that showing voltage with the red plug unplugged, is the short on the engine harness or on the red plug to controls harness?
Click to expand...

4 - Perhaps I'm getting a little dense here but I have a problem understanding this. However, if the RED plug is unplugged and the red lead of the meter is connected to the pin that is attached to the black/yellow wire of the engine's wiring harness, with the other end of that wire attached to nothing... and a voltage reading is obtained... then a short exists in that RED plug.
RESDESIGNER said:
5 - Can I run a new black/yellow wire and abandon original on which ever is the shorted harness? Also, I mistyped the motor year, it is a 1988
Click to expand...

5 - Yes, you could run a new wire.... OR you could simply cut the black/yellow on each side of that RED plug and splice in new wires to jump over that RED plug. I've done that many times as long as there are so shorts or breaks in the original wires themselves.
 
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