I always try to figure out why it Seezed first? Inspect everything. I’ve seen tight crankbearings till we split the case then they can wiggle and have play in them. They can fool us.
I just ordered a piston/rings for my 350 with low compression. Judging the age of the saw I’ll do crankbearings and seals too. I don’t trust using the old piston. I seen the pin that holds the ring from turning come loose overtime and score the cylinder. If your going to use the old piston inspect this pin closely. I’d rather replace the piston.
At first rebuilding dirtbike two stroke engines I learned really quick to just split the case and always change the crankbearings and the crankseals. The next thing I learned is to do the leak down test. Once it passes the leakdown test your good to go.
I do things right up front then I can depend in it running.
With saws your near your truck with dirtbikes we could be many miles away and over mountains and through valleys, I never had to push a bike. It’s pay upfront now or pay the second time. Do it right.