I put the motor back tougher I was surprised when I placed the head and the spark plug hole was over the valves . I set the dots together for the timing . I tried to start it fired a little . But it seems to be blowing back through carb can you help me?

I did not look over your shoulder so it's hard to tell what you may have done. Is it possible that your timing is 180 degrees off firing on exhaust instead of compression? Just a thought without all the info needed.