Small Engines (Lawn Mowers, etc.): Back fire on a Generator, tecumseh engine, low speed

Question
Hi,
Thanks for any help you may be able to give. I have a Generator, that when I start it up, it will run but when removed from the choked position, it begins to back fire. I would assume that this would be a carb problem but, what would you suggest? I believe if memory serves that it is a Tecumseh engine.
Thanks again,
Pat

Answer
Hi Pat,

I have not run across this problem before but here are my thoughts.  First, I would try adjusting the carb's mixture screws.  The high speed mixture screw is initially set at 1 & 1/2 turns out.  Then adjust it to give good acceleration and top speed, while not closing the screw more than you need to.  The low speed mixture screw is set at 3/4 of a turn out.  Adjust that, to give a smooth idle.  The 3rd screw, the idle speed screw, is set to give a low idle speed without stalling.
Next, I would suspect ignition timing or a valve problem.

Let me know how you make out.
Michael