I have heard back in the 1950s people took their two stroke mowers back to the manufacturer when the motor seized and said they always used two stroke fuel,so the
manufacturers checked the fuel in the tank by slowly heating the fuel in a pot until the fuel evaporated leaving behind the oil and a lot of the time no oil was left behind so no
warranty was given.
Probably the quickest and easiest way would be to remove the muffler and look in the port at the condition on the side of the piston and rings for scoring or a seized ring.
Powertorques with compression and starter fluid in the plug hole always fire unless the spark is washed out (eg over fueling) or the coil or module need
replacing .(this is assuming the bore,piston , rings and spark plug are in good condition)
Cheers
Max
