NO Spark 1971 Johnson 40EL71B 40hp Outboard Motor

[Mike-Boston]

Points are set correct, they open and close properly.
Both coils have same ohm reading.
I unpluged main harness - this is a mag set-up and should run alone.
I have checked all wiring connections.
Last year it ran fine.
Help.

PS at one point I had plug fire on bottom plug, so I switched coil and condencer to the one that had NO fire, and the bottom still had fire.
And now I have NO fire at all.
Help
Mike

 

[racerone]

Points must be absolutely clean.

 

[F_R]

Agreed, most no spark problems are caused by dirty or corroded points. Remove them from the mag plate, degrease them, and individually polish each contact shiny bright. Put it all back together and you probably will have spark.

In case you don't already know, be certain to use a torque wrench to tighten the flywheel nut to 100-105 ft lbs. This is important.

 

[Mike-Boston]

No Title

I did a continuity check on points -> with NO wires connected to points and used my foot to rotate prop causing points to open and close.
Points are working fine.

I did an ohm check on both coils. see attached picture. both had same reading.

 

[Mike-Boston]

With the harness unplugged -> is there anything that needs jumpered in the plug?

 

[racerone]

Nothing needs to be jumpered.----Those magnetos are very simple and reliable.------Some of us could sort this out in a matter of minutes but the motor is too far away !

 

[Mike-Boston]

I also checked continuity on plug wires,, with coil disconnected from plug wire...and recheck through coil after reinstalled.

 

[Mike-Boston]

No Title

Here is a pic of both motor sides,, thought maybe you mite see something wrong...

 

[Mike-Boston]

Is the ohm reading that I on coils -> is this correct?

 

[Mike-Boston]

Where can I get a wiring chart for this motor?