Small Engines (Lawn Mowers, etc.): Snow Blower Engine, carb settings, exhaust side

Question
I have an older model snow chief snow blower. It has an 8 HP tecumsa engine on it. It has a real bad backfire when it is running. I rebuilt the carb. on it to try to fix this problem but it did not work. When I put the carb. back on it I went by settings from a small engine repair book for the jets it said to turn them in to stop and back them both off 1 1/2 turns. It will start but still backfires. Thanks for the help..

Answer
The initial carb settings should be fine and it should not backfire at 1.5 turns out.

A couple of items to check that can cause backfireing:
1)  Defective spark plugs.  See this fairly often in Tecumseh engines.
2) Sheared flywheel key.  Not that common, but we always check.
3) Leaking intake gaskets.  Replace gaskets or use Permtex non-harding, works well.
4) Headbolt torque.  Always check on older Tecumsehs...should be 160-200 inch pounds.  Tecumsehs will vibrate headbolts loose, usually the 3 on the exhaust side.
5) Defective points, if you have them.

Let me know what you find. It could be a simple spark plug...I've seen this several times.
Eric