So I put 18# valve springs in this predator 212 hemi it has a VM22 carb and .10 head gasket. I'm very pleased with the upgrade accept it runs great for a little bit then it starts bogging on thake off for a few mins then it will stall when you give it gas and it's hard to start back up. If I turn the choke on I can get it to start but it blows a puff a smoke out then runs for a few with the choke on but when you turn the choke off it dies. I'm confused