Hi jarrod, I was just working on a stihl with similar problem and it turned out to be the spark arrestor , a little fine stainless steel mesh in the muffler that was so badly blocked it was near impossible to start so I took the muffler off and started the engine to find this by accident. I took the gause or mesh out and cleaned it thoroughly and reassembled with a good result . The mesh was hard to find because it blended in with the carbon .
