Presents
Johnson HD-25 Repair
This page is designed for educational purposes only.
The main trouble with starting is lack of spark.
Checking the condition of your coils, condensors, and points is important.
Typically, on these HD and TD models, the points are simply glazed or dirty resulting in a lack of spark.
Below on this page is the procedure for removing a flywheel to access the points on an HD-25.
The most expensive part is the flywheel puller, a harmonic balancer puller from an auto parts store runs around 40 dollars US and is worth getting if you plan on working on more htna one motor.
Johnson HD-25

Flywheel Removal and Magneto Service.

start by removing the spark plug wires by unscrewing the plug caps.
make sure your "top plug wire" is labelled or has a copper/brass marker on it so you are sure to put the top wire back on the top plug or you may have difficulties getting your project running.
Typically, I remove the gas tank before removing the flywheel, but it isn't necessary to remove the flywheel.

NEXT...

I remove the flywheels 5/8" retaining nut.

rope plate.
and, after placing the harmonic balancer puller in place, finally...

Remove the flywheel itself.

flywheel removal

exposing the magneto plate and components (coil, points, condensors).

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I will post more pix regarding HD-25 as available.
this gives you the breakdown for removing a flywheel from the 2.5 horse Johnson HD-25 made between 1946 and 1949.
next to the mag removal
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