Well if no fire up then you have issues some where so do the rule of cancelation. Step 1 full dissasemble and clean then reassemble. Clean carb aswell and make sure ur nipples arent clogged. Once youve clean it all from crank to button, then install new plug and put some after run oil in it and work the flywheel back and fourth. Step 2 do the compression test, see if the motor even has life in sleeve still. Step 3 once all above has been done and all seems good put fresh fuel in it and try again, sometimes i will prime it and put a lil in the carb so it will start right up. If still no start then the atf has ate the engine beyond repair and it would be time to cut ur losses and learn from ur mistakes.