A childhood friend of mine recently dropped off his two-year-old Husky 455 chainsaw for me to look at. It had become difficult if not impossible to start and he had taken it to a commercial small engine repair shop for evaluation. They told him it needed a new piston and ring, and as the saw was only two years old, he wanted a second opinion. Long story short, I essentially confirmed the original diagnosis and the owner asked me if I’d be willing to do the work and I agreed.
Upon opening up the saw I discovered an oiling problem or more specifically, too much or the wrong type of oil. The piston crown was covered with carbon and the piston was so varnished that the ring was actually glued tight to the piston. This is the reason it was hard to start, there was no compression as the ring couldn’t expand against the cylinder wall.
At first I thought I might be able to remove the ring, but no dice, even though I threw every trick I knew at it in order to attempt to loosen the ring. Eventually I had to break the ring to get it off the piston.
The owner supplied a new piston/ring/wrist pin kit (made by “Golf”) and I picked up two new cylinder base gaskets and a new exhaust manifold gasket. The engine was in very good condition given it was only two years old and came apart and went back together easily in a couple of hours or so. When the rebuild was compete the saw started on the first pull and settled down to a nice easy idle.
The saw owner and I had a “talk” about proper two-stroke engine lubrication and my recommended oils so as not to repeat the problem.
Though I shot video of the entire engine disassembly and rebuild I decided to not post it on YouTube. Husky chainsaw top end rebuilds have been done before on YouTube and several of them cover the subject quite well. No sense duplicating effort.
Thanks for this cool post.