Thanks Mark, I'll see what I can come up with.The impulse signal on that model comes through the flange where the carburetor mounts. You will need to make an adapter to fit the spark plug hole or the carburetor mount in order to pressure and vacuum test the crankcase.
Thanks Mark, I think I'll take your advice and just try to pop out the seals and replace them. I have two ordered.It is certainly possible to press the bearings and seals out and press new ones in, the 70cc and larger 10 Series all have a similar set up on the PTO side.
I made some special tooling to help me when pressing the seal/bearing out and again when pressing them back in place on the 10 Series saws. I did find it necessary to make a special arbor to fit the I.D. of the bearing very precisely to prevent it from collapsing the housing every so slightly causing the bearing to run out of true and try to move laterally on the shaft.
You may be able to just pop the seals out and replace them, always a good idea on an older saw and avoids disturbing the bearing. The bearings are pretty reliable as long as they have not been subjected to moisture and rusting.