No spark

[willlow]

I have a 1971 50th anniversary Johnson V4 125 hp out board with no spark I put a new coil on and a rectifier had spark one day and no spark the next day

 

[jimmbo]

Welcome to iboats
How did you determine that the Coil and Rectifier were bad?
Here is wiring diagram for you engine, in case you don't have it.

 

[F_R]

Check the voltage at pulse pack input (purple) while cranking with starter.

 

[Willyclay]

Check the engine wiring harness for deterioration of the insulation. Joe Reeves told me OMC made a change of suppliers in 1968 and your motor could be suffering like mine with multiple shorts/grounds. Good luck!

 

[racerone]

Check the starter motor to make sure it is not drawing too much power.

 

[willlow]

I have a 1971 50th anniversary Johnson V4 125 hp out board with no spark I put a new coil on and a rectifier had spark one day and no spark the next day

 

[willlow]

I replaced the rectifier because of bad wires my friend tested the coil and it was bad

Welcome to iboats
How did you determine that the Coil and Rectifier were bad?
Here is wiring diagram for you engine, in case you don't have it.
View attachment 378653

 

[racerone]

Remove flywheel.----Remove distributor cap.----Remove rotor.----Inspect anti reversing spring.----Clean all part and reassemble.----Inspect wee boots on distributor cap.-----Note , the wires are screwed into the distributor cap.----Did you take note of post #5 or disregarded that bit ???

 

[willlow]

Check the voltage at pulse pack input (purple) while cranking with starter.

My meter is old it was reading 5 volts while cracking it over

 

[willlow]

My meter is old it was reading 5 volts while cracking it over

I was getting 5 volts after the pulse pack