Yep. I have a Poulan Pro 18" that I've had for about 15 years. I cut about 6 cords a year with it. $119 factory reconditioned. Only problem I ever had with it was a crack in the coil that would open up when the saw got hot. Replacement was about $40. The only reason I fixed it was because I wanted to prove to myself that I could.
Did you check the air gap on the coil, besides the gap on the spark plug?
Yes, I set it about 0.010. I couldn't find the exact specs but I think that's about right for most small engines.
I cann't confirm the 0.010 gap but have always just used the thickness of a paper matchbook cover or a good business card.
The rust doesn't effect the magnet to make spark. The rust will cause the air gap to get smaller to the point it rubs the coil, and that will effect spark. So minor rust coating is no big deal but crusty buildup will.
.010” is too small of gap. The matchbook cover described would be between.020.-.040” open the gap and spark should be present. In the past I have used neon bulb to verify spark strength over shocking my self. You can use voltmeter on high dc voltage setting at least that would help with strength of spark. Mind you negative leads both bulb and or meter to known ground. I have 3 Poulan saws only use synthetic fuel in them to assure stability.
I bought one of those lightweight plastic Poulan ones many years ago when they first came out. My neighbor got one first and I really liked how light it was. The interesting part is both saws failed after about the same amount of operating time and the same failure mode. One of the screws on the flywheel vibrated loose and ended up getting wedged between the flywheel, fuel tank and chassis putting holes in the plastic.
FYI speaking of gap on magneto not gap on spark plug
