Hey Ody!....BLR has heard me say the magneto area so much, she got thinking it was the magneto itself.....I'm pretty sure you know all of this from the service manual pictures, but this description may help others later down the road....and am very sure that I know why the sprag assembly went bad and no-one else's should have this problem really...
The magneto cover has to be pulled and set aside....then a specialty puller screws onto the magneto shaft with a doweled button to insert in the shaft end to prevent the puller's bolt from doing damage....when you tighten the puller's bolt, it presses against the button and pops the magneto rotor off, then set it all aside.....
That is the one-way sprag directly behind the magneto rotor with the flywheel ....the sprag's job allows gripping when rotated one way, but free-wheels if turned the other way...as the starter torque is applied, the sprag grabs hold and cranks the engine thru a series of gears....as soon as the engine spins faster than the sprag assembly is cranking, it instantly free-wheels from then on....this is the equivalent to an automotive style starter's bendix...
When your looking at the "stuff" behind the magneto cover from rear to front, you will see the starter motor teeth, then a reduction gear, then an intermediate gear, then the big flywheel/sprag unit directly on the crankshaft centerline....3 bolts and off comes the problem child sprag....
