5 year old engine is on a lawn blower. Ran AOK until a month ago. Decarbonize about every 1.5 years
Symptoms have been the same for the last 30 days. Starts on 2nd or 3rd pull. Occasionally when starting have to give it full choke and then unchoke and repeat. Also when that occurs it will not run at idle. Eventually that clears up and it runs for 5 to 10 minutes, then starts missing and finally quits. After a few minutes I am usally able to start it and it again runs fine -even though still hot - sometimes for longer than 10 minutes.
Decarbonized combustion chamber and around valves. Not much accumulation. Valves appear to seat OK. Installed new plug properly gapped. Ignition system is the newer type without condenser or points. Spark tests OK just after it misses and quits.
Totally emptied the gas tank and refilled with brand new gasoline. Same symptoms
To me it sounds like the carb needs a thorough cleaning OR one of the valves is not closing after the engine gets hot
What would any of you recommend next: (1) Clean carburetor, (2) Grind valves and check clearance, (3) Go for a rebuilt engine including fuel system
