Chainsaw Repair

Actually it sounds more like a crankcase gasket which is a big job.  The most fun will be those crank rollers on the rod.

I would drain and clean both tanks and air dry.  Then fill the gas tank, and feel along the seam for moisture in the oil side, it will
probably be fairly obvious.

You can pack some heavy wheel bearing grease around those rollers on the lower end of the rod to hold them in place?

For those that wonder what's going on here, the 009 only had one counter weight on the crank and the rod slid off and on the crank from one end after that side of the case was removed.

Taking a flywheel off the "redneck way" without the official puller works better if there are two people.

One person holds a pry bar on each side while the other taps the nut threaded even on the shaft with a dead blow hammer.

It wouldn't hurt to have warmed the flywheel up around the hub area with a heat gun ahead of time?

Most of the Stihls used a blind sleeve with threads on the end to engage the threads in the hub of the flywheel to pull it off.

Just thread the flange nut down, but 1/2 turn from touching the flywheel..  Hold the flywheel with one hand, and set a socket on the nut, and rap it with a hammer, will pop right off.

I will get you the part number later today or tomorrow. I agree with fish the puller from stihl you thread on and hit the end with a hammer. I always try and support the clutch side of the crank to prevent any side ward movement. Don't think it is necessary put good practice. Not much on prying on things something usually ends up broken or bloody. Also you can give it a pretty good hit  to break the tapered seat.