Is the breather in your fuel cap clean? Try running the mower with the cap very loose or even off (if you have a clean area where it won't get dirt into the fuel when it starts).
If it runs, then clean the breather or replace it with a new cap.
Is the breather in your fuel cap clean? Try running the mower with the cap very loose or even off (if you have a clean area where it won't get dirt into the fuel when it starts).
If it runs, then clean the breather or replace it with a new cap.