I was given a toro lawnmower it will start and then stop I have replaced the oring behind the carb and I have replaced the full line . It acts like it has a vacume lek but I do not know where it is

I was given a toro lawnmwer it will start and then stop. I have put a new spark plug in. I have replaced the oring behind the carb and I replaced the ful line. I can keep it running if I squart wd40 in the carb.

"wd40" is this a mistyped word, didn't you mean carb cleaner or fuel? Tell us more. Did you test the carb float?

Sounds like you need to take the carb apart and clean it.