Picked up a used 026 with 18" bar. At first it wouldn't start so I took off the air cleaner which was all plugged and cleaned it up and got it going. It still takes a while to get it running when cold. It has a torn black rubber button or plug on top which I thought might be a compression release but it doesn't move when I push it. I put a new chain on it and it revs up nicely but a little way into a cut it bogs down badly, I can lean harder on my Makita UC 4000 electric. This is in a 12 inch log which I would think should be no problem for it. What do you think, too lean maybe?