Lawn Boy 8243 surges and stalls when choke is off, runs great with choke on, have cleaned card. What would cause this? Would a defective primer cause this?
Just to add what Hammermec said, you're saying it's with the choke on...on all the way or slightly off full choke? If it's running great with the choke slightly off from full, then I have seen this issue with a bad governor spring.