this happened after about a half of tank of fuel. Started running goofy so took it back to the shop and failed vac and pressure test miserably. Got pretty lucky and didn't wreck the new piston and cylinder
To be chewed up, you gotta think they spun and there are burrs in the clamshell or cyl bearing area. Or the rubber is defective and flaking? I've never replaced the bearings/seals on a 42cc Poulan. I do put a very thin layer of Motoseal on rubber before re-assembly.