After 30 years, my chain saw quit..

I think you should cut some more firewood...just in case!

 

I agree. Give yourself piece of mind when you want to cut. If that saw had low hours and hardly used i can see keeping it as your main saw, but like stated it doesnt owe you anything.

I have a nice MS261 pro model saw for sale. Original owner bought Sept. 2019.

 

Well I got me some sassafras I think. Smells real nice. Super wet. But super delicious indeed!

 

It is handy. If you see a spark jump with that tester, then you have plenty of spark to get it going. You can even hook the ground to the spark plug and the other piece to the spark plug wire and it will run the saw. This is used to see if the electrical system is breaking down after it warms up.
As for the rust on the flywheel, Briggs and Stratton, as well as other manufacturers claim that rust does not affect spark. I had a wood splitter that wouldn't start after sitting for a while and all I had to do was pull the cover and lightly sand off the rust. It would fire right up after that. The rust was thick enough that it would close the gap. In your case, that debris that was on the magnet could have reduced it's ability to build enough energy for a strong spark. Good luck with it and sounds like you still have a few years left in that saw. I have one that has served me well for 38 years (it was my primary user for a long time and now I just run it occasionally to keep it in good repair).

 

4 out of 6 of my Stihl saws are over 25 years old. The 044 won't run right now. I believe it needs new seals and rubber parts since they have never been replaced.

I just got a free 180 that sat for 3+ years. Washed the fuel tank out, put in new mix and the saw ran and idled. Clutch drum needed replaced, so the saw was run alot in the past. $18 and the saw runs and cuts good enough to cut hedge.

A few new parts and the saw should run again.

 

I still have and use a 1978 162se, runs great for a 44 year old saw