New here, I have a Stihl cm-180 chainsaw, used seven time in five years! Only used for pruning small tree branches (up to 6 inches thick) Now the piston and cylinder want replacing at €250! (about $230US)....Last Stihl product I will buy. Only thing I can think of is that as it was so long between usage that there was no lubrication left in the cylinder...it had evaporated so when I started it up it was running dry....bad design. Since looking on the web a lot of people seem to think it is OK to replace the piston every 50 hours.....I am going to buy a battery Ryobi next time....at least they work when you switch them on!