I have a 79 k5, and a Rochester carb. I replace the choke due to it was broken. It ran high but when we adjusted it and it wouldnt turn over. So i replaced it and now when I try to turn it over I got fire in the carb. I need to figure out how or what I need to check now. Any help?

 

If you are having a back-fire, that could be because the mixture is too rich. If I remember correctly, an overly rich mixture burns slowly so that when the next intake stroke occurs there is still some burning fuel in the cylinder and that ignites the mixture in the intake runners. But you could also have the valve timing off I guess.

I don't know Rochesters but the problem could be that the jets are too large. On Autolite carbs, it is easy to forget to put the jets in and you get gobs of fuel available.

 

Just to get the situation right. It's a bit difficult to diagnose without an idea of what has been done.

You have taken the carburetor off the Blazer, then disassembled it, and fixed something on the choke "inside" the carb?