Small Engines (Lawn Mowers, etc.): Lawn Mower will not turn over, craftsman lt1000, spring extension

Question
We recently received a broken Craftsman LT1000 lawn mower.  The front axle was broken off.  We got the barts and put the mower back together, however there is one part attached to the blade engauger that has a cable and then a spring on the end.  We have looked over the schematics but cannot find exactly where it goes.  The part number is 152 on the model 917271820.  We thought we had found where it went and we tried to start it.  We realized that the battery was really dead, so we jumped it and it did run.  I drove the lawn mower around the yard but when we tried to engage it the mower died.  The throttle could not be pushed in all the way without the engine dying.  We noted that the gas was low and added more plus fuel stabilizer.  We checked the oil and added to it as well.  When we tried to jump it again it would not turn over.  It starts to turn but then stops and the battery goes to the negative amps.  We bought a brand new battery and tried that but we got the same thing.  I think the engine has seized but I'm not sure why.  Is there anything that you can suggest that we do?  Keep in mind I am a novice but willing to learn.  
Thanks

Answer
 Hello Jaclyn:

 Send me the Make, Type and Code Numbers Off of the Engine, Please. With these Numbers I can View a Breakdown of the Engine and Better Assist you. The Cable with the Spring goes Thru #4 and the Clip #149 Holds the Cable Shield In this Bracket on the Deck. The Spring Itself Hooks to #147, the Spring Extension. When the Cable is Pulled it will Pull the Pulley on the Piviot to Tighten the Belt for the Blades to Turn. It also Sounds like the Carburator needs to be Cleaned and Rebuilt. The Safety Switch on the Seat May be the Cause for the Engine to Die When the Blade Lever is Moved. Hope this Helps. Let me know whta Happens, Please.

 Good Luck

 Respectfully

 John