Presents
Johnson HD 25 Repair
This page is designed for educational purposes only.
Johnson HD-25

Magneto service
including coil replacement follows
the mag plate removal
from the engine block as outlined on that page.


Next, continue by turning the magneto plate assembly over and removing the two spark plug wire retaining clips.


next...


remove the coil retaining screws. There are two on each coil.


Next, locate the screws on the points.
remove the screw retaining the wire from the condensor and coil.


next, turn the mag plate over again and locate...

the coil ground wire flathead screw. On the top side of the mag plate is a 3/8" nut.

next, we remove the points for cleaning by...

first removing the point retaining flathead screw.

lifting the point assembly and removing the ground wire on the point's second screw.


shown above are the two small brass screws that hold the point pieces together.

BE SURE TO TAKE NOTE OF LOCATION OF POINT PIECES.

shown apart in the picture above.

and make sure not to lose the two small bushings inside the point screw holes.

reassembly of the points and replacement of the coils in reverse order.

Point adjustment is simple.
Line up the "top" on the magnet and loosen the point screw

and slide the point assembly forward with finger or gently slide backward with screwdriver to adjust to .020 inches.
Retorque the pont screw, repeat for second point and your good to go.
Check for spark, if no spark, clean points and reset as outlined.
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