Stihl 050AV

[dirtsci]

My son has an old Stihl 050AV chainsaw and I'm trying to get to run. I've rebuilt the carb and checked it out. When I crank the engine it coughs and backfires. The low and high needle valves are set at about 1 full turn out. Its' not the plug, since I have a hot spark. Any ideas? Could the timing be off?
thanks.

 

[Lakeside53]

Sure sounds like timing or your points need adjusting. If they are pitted or things just wont work right... maybe time for a new condensor