My Stihl MS170 sat for years before now I need it. Fresh gas with Stabil pull and pull, nothing. Pull the plug, damp from gas replace plug, pull and pull nothing. Pull new plug lay on top, pull looks to be spark but not fat. Pull cover off, starting fluid into air intake to carb, nothing. Zero, thinking a weak spark ordered new coil and new Carb just in case. Since it would not start with Either I thought that was a clue. Comments?