My 2150 chainsaw was my favourite longest serving Poulan. It has the separate choke and kill switch which I prefer. Now won't start and extremely hard to pull almost like timing too advanced. Good spark, fresh gas, new gas filter, new fuel lines, new primer bulb, 40:1 mix. Remove spark plug and turns over smoothly and easily. Insert plug and leave plug wire off and it seems to pull easier, or my imagination. I'm not stuck for a saw, I have three more newer Poulans. I just hate being stumped by a little two cycle motor. It has the Walbrow carb. I don't suspect the carb because injecting a small squirt of fuel still no fire. Any ideas out there? Edit....also removed muffler to make sure it wasn't clogged...no difference.