New coils no spark 1956 15 hp evinrude

[The Boat House]

• This reply was modified 4 years, 1 month ago by The Boat House.
• This reply was modified 4 years, 1 month ago by The Boat House.

[jeff-register]

Checking the secondary winding is easy. Go to your highest resistance setting on your meter. Take one meter lead to the magneto plate & the other lead to the end of the spark plug wire. That will measure the resistance of the secondary winding. Also leave the lead on mag plate & test for resistance between the mag plate & the block of the powerhead.
Reason I suggest this test I had resistance between the two & had to add a bonding wire between the mag & block.
When building a mag for a 2 cylinder motor you have 2 complete magneto systems. Mine had a current reverse & the output from 1. coil was going into 2. points & turning them gold they got so hot. I had cleaned all mating surfaces with acetone & lightly lubed it. With a bonding wire problem was solved, easy start motor now. If you have very high resistance testing the coil you may have a blow-out where the coil arced from the winding to ground. This would cause a break in the winding only connected by a piece of carbon where a winding was there. Carbon is a material used to make resistors too.

[trainsnmore]

Good afternoon,
I did the test. Top plug wire showed19.7 and the bottom plug wire showed 8.7. Mag plate to block zeroed out. Hope this is good. Does this show that the plug wires are good to the coil. Trying to eliminate why I have no spark. Timing was set with a meter from marks on coil plate and flywheel.
Gary

[jeff-register]

Something odd about that much of a difference in resistance. Time to measure the coil itself connecting directly to the hi voltage (secondary terminal. ) and mag plate. You may have bad spark plug wire and or terminal rusted. If I may ask what resistance scale did you have your meter set on? The meter should say ohms, then times 10, 100, 1000 & so on to meg ohms. I have no idea why with new coils would show that much of a difference in resistance other than bad wires or connectors. What kind of spark plug wire was used? Must be copper wire, solid or stranded Yes when you show no resistance on the mag to block that is a great reading.
Check everything like the factory wire terminal where the connector is crimped on the wire. Electrical is like a chain, one bad link causes an open connection & system will fail. I in the past have always soldered the connector to the wire. Just added insurance it will not fail in a humid place.
Please pay attention to details & keep the magneto super clean. Everything will conduct electrical even air. As in lightening. Wish you were in Phoenix Arizona, I would help you in person,
Anyone have anything to add to my suggestions?

[crosbyman]

yep pull the coils test individually the results should be 4-8Kohms the same from the end of the plug wires boot .. if not …..look for corrosion..better yet just replace the wires and recrimp the clips

Joining AOMCI has priviledges 🙂

[Mumbles]

It might be time to check the condition and continuity of the spring terminals inside the spark plug boots. They should be nice and clean with no sign of rust or corrosion and be making a good contact with the plugs wires copper core.

[yumagoat]

Put a lot of coils in fleetwins and just had the same problem with new coils on a 55 aquasonic 15…..put old coils back in and the spark was fine. The new coils were chinese made and I probably cannot say where I got them here but if you ordered them the largest online store be careful…they did allow me to return them for credit. I do not think they generated enought secondary voltage to jump a tiny gap.

[cajuncook1]

If everything checks out. You may have to use the old coil laminates and put the new coil core on the old laminates. The aftermarket brands can have laminates that are not the same measurements and can cause an issue with improper laminate to flywheel magnet gapping. Thus causing no spark, but you must recheck your ignition plate. Could be something simple as poor contact. Clean all contacts going to ignition plate and the ignition plate to the motor.

Also, take a picture of your coils’ laminates facing from a horizontal view. Want to see if those laminates are mounted / positioned flush with the Magneto plate’s line up bosses.

https://youtu.be/r7A6d8me0Gw

Cheers,
Cajun

• This reply was modified 4 years, 1 month ago by cajuncook1.

[Monte NZ]

Interesting reading Tub’s post re energizing the magneto using an electric drill, in that about a year ago I was having similar problem with the magneto on a British Seagull I was restoring and spinning the motor over for several minutes brought the spark back again……. If I remember correctly, I heard of it from a chap who services Seagulls here in NZ.

Monte NZ

[crosbyman]

gents…. I think we still do not have valid results of proper testing on the basics……..mainly :

… resistance of each coils windings (primary & secondary) on their own
… and then, all the way from plug boots to secondary windings of each coil ( above posted results seem suspect)

“yep pull the coils test individually the results should be 4-8Kohms the same from the end of the plug wires boot .. if not …..look for corrosion..better yet just replace the wires and recrimp the clips”

Joining AOMCI has priviledges 🙂

[Author]

Posts