No spark

[Rand]

I just moved with my 50 Merc from Atlanta to Idaho.. My Merc seemed to run ok with the cold air and altitude change. Took it for one little cruise around town once. The very next time I went to start it.. It kinda kicked over then it just cranked and cranked. Pulled the dizzy to coil wire out and jumped between the two. Yup no spark =(. Where do I start to find out why?
Thanks in advance! Wish I could post a picture of my Merc with the grand tetons in the back ground.. I forgot how?

[VeryTangled]

Electric to starter seems ok. How about to the plugs? Crank it with a plug wire nearby a ground and it should arc.

[JSeery]

See if you have voltage to the coil.

[Rand]

JSeery. Pls tell me the simplest way to do that. I have a volt meter but am a dumbbell when it comes to electronics

[50fordcoupeman]

No help here yet...............just wondering where in Idaho?

[corvette8n]

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https://www.fordbarn.com/forum/showt...ting&showall=1

A thread on coil testing.

If you are trying to post a picture and it doesn’t work, try emailing it to yourself to reduce the size and then try uploading that, also crop the picture it usually lets you upload it then.

[Anteek29]

That's what my wife said...

[backrodebob]

disconnect positive and negative wire from coil take meter set to 12 V, turn ignition on touch positive to positive wire ground to engine ck reading should be 12 plus volts
to test coil first set meter to ohms that’s the image that looks like a horseshoe now to 0 meter touch probes together whatever reading is deduct when you test coil, positive probe to positive terminal negative probe to negative terminal this is your primary should read between 1.4 to 2.0 To test secondary positive probe to positive terminal negative probe two coil wire terminal should read between 8000 to 13,000
Hope that helps!

[oldford2]

I would try the easy things first. Try changing the condenser.
John

[Rand]

I'm really baffled. I'm still having a hard time figuring out how to test the coil, points and the condenser with a voltmeter? Took the distributor cap off and ran Emery cloth through the points.
Turn the key on and crank the motor which produced the smallest spark at the points.
Cap? Plug wires? Weak coil? Weak condenser? Please help! Thank you

[cas3]

If you cleaned the points with emery paper instead of a real point file, you should then drag some paper thru the contacts, as emery grit is still some times left behind, then no good contact. Lets then go back to post #3, JSEARY , how much voltage is at the coil. take off the wire coming in from the harness, not the one going to the distributor, then turn on the key in the car, then with your meter connected to the wire from the harness, and the black ground lead grounded to the motor, how much voltage is there ? report back and we can go to step two !

[Rand]

Cas3... Thanks for making it simple for me
Did as you said and got 6.20 volts.
Anxious to know what step two is?

[Tinker]

https://www.youtube.com/watch?v=bF3OyQ3HwfU


.

[cas3]

Tinker is...partly correct. too much for an earlier car with a resistor, but the 50 merc should have a can coil on it, with its own resistance built in. I would next go to step two, check the coil itself, post # 6

[Rand]

Cas3 before I ran the Emery cloth through points I changed out the coil with a coil that I had on the Shelf with no effect. I also changed out the condenser with one that I had on the Shelf too

[Rand]

Tinker... Nice YouTube video thanks

[Tinker]

Originally Posted by cas3

Tinker is...partly correct. too much for an earlier car with a resistor, but the 50 merc should have a can coil on it, with its own resistance built in. I would next go to step two, check the coil itself, post # 6

Yes I originally posted about the underdash resistor and voltage, then reread this was about a 50 merc and deleted.


No spark is coming from something going on in the dizzy I'd guess, since you've changed out the coil and condenser. But I'd test everything. Assuming the points are good and gapped and the timing is set.

[Rand]

Tinker.. Cas3 .. Can either of you explain in simple terms how to test coil, points, and condenser for this electrically challenged Flathead lover? Thanks in advance

[Rand]

Years ago my dizzy went copout.. So I sent it off to Bubba for a rebuild. He found the wire inside the dizzy was grounding out..not the case this time since I saw a spark in the points when I cranked the motor with the dizzy cap off..

[Tinker]

Could be you need a different cap and rotor. Testing the coil is posted in #6


Follow it through the line. You have spark at the points.