Chainsaw Happiness

The chainsaw is one of several essential items on our farm. Without it we cannot either prepare firewood or clear land. Freezing and starving is the result. The failure mode of our chainsaw was sudden engine stoppage. I suspected the issue was with the electrical system, considering the sudden transition from excellent performance to paper weight status.

As Betty remarked in her comment, exhaust manifold screens can get obstructed, causing starting and operating problems. I actually experienced this problem when the saw was new, since the mixture controls were set up by the Stihl legal team, apparently, who were concerned that if the saw should develop full power, someone might get hurt! 12 years ago I leaned out the combustion mixture (more air, less fuel), increased max engine speed, and have never revisited this problem.

My basic plan was to remove the electrical harness from another saw that I had inherited from my father, but was non functioning, having fallen down the stairs. Really. We have a multi-story utility building and one day while retrieving the saw in the dark (who needs lights, I know my way around!), groping about the storage shelving resulted in the saw bouncing down the stairs. Almost as spectacularly as the time I unloaded a 1000 pound round hay bale on a slope that went rogue, disregarded my threats and body english to blast its way through a new fence.

Electrical harness from the “spare parts” saw

Although my intention was to swap electrical harnesses, the big Farm Boss had a convoluted disassembly scheme, and I could not see how to safely remove the carburetor from the engine without damage. So I cleaned the electrical contacts, firmly seated the spark plug connector, and put the beast back together. Works great. Back in business.

January 17th, 2010