1977 75HP no spark (newbie tracing fault)

[touch107fm]

Hi guys

In need of some help / advice.

I bought my first boat about a year ago and I have being slowly restoring it bit by bit. Its a simple half cabin with a 1977 75hp evinrude. Over the past year or so I have learnt so much about motor engine but I am still learning.

My problem I have had the boat out on the water last week and now on Monday I brought it down to the water again but no joy it would not start.
I had a similar or the same problem a few months back I though it was resolved, I have been going crazy trying to fix it.
Being following the troubleshooting guide on the CDI electrics website.

Technical Support | CDI Electronics

So my problem is I have no spark on all three cylinders.

So far I have:
Removed yellow/black cable from power pack - no spark
Unplugged wiring harness and jumping starter motor - no spark
Cleaned all the contact and inspected all the cabling / wiring - no spark
Tried switching the key switch - no spark
I want to complete the next steps as per the support guide but dont fully understand how to test correctly (I feel ashamed asking)

I am referring to the tests for the:
Stator
Rectifier
Power pack
Coils
Base timing base

So here is the thing I dont know fully understand how to use my multi meter



When it say's to measure:

Check the stator and timer base resistance and DVA output as given below:
WIRE READ TO OEM RESISTANCE CDI RESISTANCE DVA (Connected) DVA (Disconnected)
Brown Brown/Yellow 400-600 400-600 150-400 V 150-400 V (*)
Black/White White/Black (all) 10-20 30-40 0.6 V + 0.6 V + (#)
Black/White Engine GND Open Open 150-400 V (a) N/A
White/Black Engine GND Open Open 150-400 V (a) N/A



What value on the ohms should I be using to measure these, also do you measure these in connected to the powerpack or no connected. Is this also tested with the ignition in the 'on' position. If anyone can explain or give me an idiots guide on how to test these that would great.

For the DVA values what setting on the mutli meter do I use.

I dont want to just start replacing bits for the boat, I am treating this like a big puzzle.

Another question, I know some of you will come back and say get the manual, Q. what is the different (apart from price between these :
1977 Evinrude 70 75 HP Outboard Motor Workshop Service Repair Manual Book | eBay

And the online one for general evinrude motors

Evinrude Johnson Repair Manuals Service Manuals

Any help would be greatly appreciated.

Darragh

 

[Bosunsmate]

Re: 1977 75HP no spark (newbie tracing fault)

For the resistance of the stator use the 2000 ohmn setting between the two wires that the troubleshooter tells you to test coming out of the stator, disconnect it from the powerpack.
For the timing base resistance use the 200ohmn setting.
What you are doing is using the lowest ohmn setting which is in the range of what you want to test.
TO measure the voltage correctly you need a DVA meter. What you have there is not a DVA capable reader, its the same as mine. You can get a reading of voltage on it but it wont be the peak AC voltage which is what those values are.
Since you have no spark on all of them id guess that you will find out what the problem is using just ohmn testing. What you can also do is test those same wires to ground. If you get a reading on any of them it would indicate a leak to ground which will cause a no spark condition. It happens quite a lot on motors of that age as the wiring cracks over the years and as the timing base and stator wires turn as the throttle turns it slowly starts rubbing away its insulation until it starts grounding out

 

[Bosunsmate]

Re: 1977 75HP no spark (newbie tracing fault)

When doing the testing to ground make sure it is just your meter lead touching engine ground and not the wires from the components.

So you put the black lead on engine ground and then touch the red lead to each of the wires mentioned above and with the reader in the ohmns setting 2000 make sure it doesnt suddenly give a reading- that would indicate a short

 

[Bosunsmate]

Re: 1977 75HP no spark (newbie tracing fault)

Also disconnect powerpack to check timing base ohmns.
Ignition off

 

[emdsapmgr]

Re: 1977 75HP no spark (newbie tracing fault)

The service manual on ebay is a genuine factory manual. That's what you need. When testing the stator and timer base, I like referring to the output voltages for both devices. I don't think this factory manual states condemning output voltage values-that was used in later factory manuals. You can find these values for this older model in the cdi online (cdielectronics.com) ignition troubleshooting guide, page 34. For instance the output voltage from the stator should be at least 150 volts. The output voltage from the timer base should be at least 0.6 volts. Measured when cranking by a DVR type voltmeter, when cranking the engine at least 250 rpm's. You will need a special DVR to correctly measure this voltage.

 

[touch107fm]

Re: 1977 75HP no spark (newbie tracing fault)

Hey Guys

Many thanks for the replies, I have spent the afternoon researching so I feel more confident about fault finding the issue.

I also have Fluke 113 multimeter, I will see if I can get a DVA type



I will keep you posted.

 

[Faztbullet]

Re: 1977 75HP no spark (newbie tracing fault)

The only meter with a builtin DVA is the analog ESI-530 which is copy of Merc meter(may even make Mercs). Yopu can build or buy a DVA adapter. This meter is sold on Iboat and several other sites
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=dva multimeter

 

[touch107fm]

Re: 1977 75HP no spark (newbie tracing fault)

Hey guys

An update:
I spent some time on the boat this morning. First test was on the coils. One of them is dead.

I tested it by putting red prong from multimeter in spark plug cap and black prong on orange cable? Is this the correct way to test.

Get a reading from 2 out of the 3 coils.

Would this cause no spark all over ??

 

[Bosunsmate]

Re: 1977 75HP no spark (newbie tracing fault)

I have no idea if its the correct way but if they arent all the same then one of them is playing up.
To answer your second question, no, one bad coil wouldnt cause spark loss all over

 

[Bosunsmate]

Re: 1977 75HP no spark (newbie tracing fault)

I have no idea if its the correct way but if they arent all the same then one of them is playing up.
To answer your second question, no, one bad coil wouldnt cause spark loss all over

 

[Bosunsmate]

Re: 1977 75HP no spark (newbie tracing fault)

I have no idea if its the correct way but if they arent all the same then one of them is playing up.
To answer your second question, no, one bad coil wouldnt cause spark loss all over

 

[emdsapmgr]

Re: 1977 75HP no spark (newbie tracing fault)

Swapping coils is another good way to test them. A faulty coil will take it's fault with it when it is moved on the engine.

 

[touch107fm]

Re: 1977 75HP no spark (newbie tracing fault)

Hey Guys

I was ready to put a sledge hammer to the motor yesterday, I took some reading from the stator and timing base as mentioned above.

They came back with a reading of:

Stator 687
Senor 1 32.46
Senor 2 32.46
Senor 3 32.46

I am not 100% if I am doing the correct tests but I dam it I am learning!!!

I also stripped the control box and swapped back in my old key switch.. No joy same again, swapped back in the key switch no joy with spark.
Went and bought new plugs and disconnected the faulty coil from the it fired!!!

I dont think it is fully fixed as I havent done much so think it will be intermittent with the spark.

I am getting a secondhand coil today as a new has to come from over east.

Will keep you posted.