150 merc wont start

[steplift20]

i held the key in and i here the click, she wants to start but shes not,cranks then sputters
i did add startron to the gas

[steplift20]

last year my mech replaced a check valve with a used one cause he didnt have a new one but he said they very rarely go but i do have a new one in my box iam going to change that just to make sure its not that