Echo cs680

[Old Plumber]

I have and older (2009) cs680. Under used saw. Won't start. Has fuel, has ignition. It won't even kick, backfire, and no reaction to ether (starting fluid).
I have NEVER in over 60 yrs. had an engine unresponsive to ether if it has spark.
Any ideass/help?/
thx, old p

 

[holeycow]

Timing

plugged exhaust

 

[wcorey]

Sheared flywheel key is always suspect, assuming there's also adequate compression.

 

[Gord404]

pull the muffler and check your piston for scoring.