Makita 6401 with 84cc jug, 150 compression, fouls plug immediately with smoke coming out the exhaust when trying to start. Never attempts to fire. It has spark according to the tester and the air filter off at this time. I have not pulled the exhaust but if it never tries to fire, why. I had a post earlier that the welsh plug was out by the needle valve and I installed a new carb. I've never seen anything like this and wouldn't you know trying to repair for my best friend and usually, I always fix whatever is in front of me. Don't really want to take the new carb apart but. Hopefully, someone knows the answer and thanks for any help.