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Tan
Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 10620
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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1974 85 hp evinrude starflite has lost spark to all

Customer Question

1974 85 hp evinrude starflite has lost spark to all cylinders and I dont know why. It has been running great and then all of a sudden has lost it on all 4 cylinders. Please help
Submitted: 1 year ago.
Category: Boat
Expert:  Tan replied 1 year ago.

Hello. My name is Tan.

This may take more than one rerply to solve your issue.

Disconnect the black/yellow wire from the power pack # ***** now check for spark. Do you have spark?http://www.boats.net/parts/search/BRP/EVINRUDE/1974/85493B/IGNITION%20SYSTEM/parts.html

Also check that you have a good ground to the plate that the power pack is bolted to. There should be a ground wire # ***** running from the plate to the engine.

If still no spark do you have a peak reading volt meter or an ohm meter to do some testing with?

Post back with findings.

Customer: replied 1 year ago.
Took power pack cover off and I dont have a yellow and black wire underneath. Which one is it that I need to disconnect?
Customer: replied 1 year ago.
Nevermind I found yellow and black wire. It is 1st ine on bottom row but even when. I disconnect it I still have no spark to any of the cylinders
Customer: replied 1 year ago.
Expert:  Tan replied 1 year ago.

Did you check the ground to the plate?

Do you have an ohm meter? We need to check the brown to brown/yellow. With the ohm meter. Test between the 2 browns we need 400-600 ohms

Customer: replied 1 year ago.
I wilk try that when I get home tonight. Do I need to leave the yellow and black wire disconnected or reconnect it to do this test?
Expert:  Tan replied 1 year ago.

OK. If the ground to the plate is intact then you can reconnect the black/yellow. To test the stator disconnect the brown and the brown/yellow and test between the 2.

Customer: replied 1 year ago.
I made sure it had a good ground
Expert:  Tan replied 1 year ago.

Ok then the next test is the stator ohm test. 400-600 ohms. Then the final test is the timer base. Both of these components are under the flywheel.

Locate the timer base wires and test between cylinders #1 to 3 and #2 to 4. Should be 10-20 ohms.

Customer: replied 1 year ago.
Checked stator wires and resistance was 638 ohms. Tested all the timer base wires and they all were 9-12 ohms
Expert:  Tan replied 1 year ago.

Ok the stator is out of spec but it is close enough it could still work. So now we are at the point where it will take a DVA adapter to verify the stator or the power pack. The DVA adapter tests the actual peak volts the stator puts out.

Here is the DVA adapter we need to verify the output. Many times the stator or the timer base will be out of ohm spec and we know what the problem is. But when it is this close we have to test with the DVA.

https://www.google.com/shopping/product/6839087715725588451?rls=aso&client=gmail&q=DVA+adapter&authuser=0&sa=X&ved=0CH0QuSRqFQoTCNeA2464-scCFRA7iAod2KkO0w

Customer: replied 1 year ago.
I will have to order it and it will probably take a week to get here? Anything else I can do in the meantime to get us further along with testing?
Expert:  Tan replied 1 year ago.

Not at this point we have done all the testing we can. It all boils down to this point we have reached here with the use of the DVA.

Customer: replied 1 year ago.
This boat also has an aftermarket toggle kill switch. Could that be part of the problem? If so How do i test it? Or could it possibly something else in the key switch?
Expert:  Tan replied 1 year ago.

That is the purpose of disconnecting the black/yellow wire at the power pack. Since you disconnected the black/yellow that isn't the problem as you didn't get spark back. The black/yellow eliminates the key switch and the kill switch as the failing component.

Customer: replied 1 year ago.
My dva adapter finally came today but I have never used before. Does it hook up differently to my multimeter than when checking the ohms? What are the values are looking for? How can I tell if need to replace the stator or thex ppwerpack
Expert:  Tan replied 1 year ago.

The DVA works on DC volts scale. Then you connect the meter red lead to brown and the black meter lead to the brown/yellow crank engine what is you meter reading> The meter has to be able to read up to 400 volts DC scale. If you have voltage between 150-400 volts the stator is ok. If less than 150 the stator is bad. Then we have to test the timer base.

Post back with the results of the stator reading.

Customer: replied 1 year ago.
I hooked up the dva to multimeter and then tested as you said. It never registeted anytbing it stayed at 000 entire time while making engine spin. Do I have it set to the wrong place on my multimeter? Do wires have to be connected to power pack or disconnected? I tried both ways and still no changes on reading? And now aftet last time making it spin I heard a loud sizzle in my control box and now it doesnt do anything at all. What do you think it was? I opened box and looked for burnt wires and saw none that seemed to be.
Expert:  Tan replied 1 year ago.

Stator wires disconnected. Did you have meter on DC? Try meter on AC. I don't no the make of your DVA so it could be different. If still no voltage then the stator is bad.

Now for the sizzle I don't know test for voltage on the red wire of the key switch do you have voltage if no voltage check the fuse on the engine next to the start solenoid. The fuse is an inline fuse 20 amp.

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