Hi. I have a mighty merc wood splitter with a 5hp tecumseh enduro engine that won't start. Spark is good. Cleaned carb would fire but not run, won't run when fuel is put in spark plug hole, would fire off either once or twice real quick. Plug seemed dry. Replaced carb and same results. Carb does prime. Checked valve movement and it is good. Checked flywheel key way it is good. Fuel is clean and fresh. Kind of stumped at this point any help would be appreciated. Thanks.