Small Engines (Lawn Mowers, etc.): 31c707 B&S Engine Turns, wont fire, and bangs, briggs stratton, rod bolt

Question
I've read through the answers and have seen some comments on disconnecting the coil to check for spark.  I will do this.  But I took this engine apart and reassembled it with no repair manual.  Everything went back together fine and I didn't have any extra parts!  But now it will crank a few times and then bang real loud out of the exhaust.  Perhaps my coil isn't in the right place.  Perhaps the throttle adjustments are ever so slightly off.  I'm certain that I aligned the crankshaft to the camshaft properly (matched dots).  The flywheel fit fine on the key - is there any other adjustment?  Just gapped valves to .006 & .008" intake & exhaust respectively.

Motor was working fine until it threw a connecting rod bolt and destroyed my connecting rod, so I'm sure that it's just a minor adjustment...

Model number is 31c707-0230-e1 Briggs & Stratton, c. 2005

Thanks,
Jim

Answer
Jim,


   Since the rod was destroyed its evident the rod needs replaced so here is the Illustrated manual and parts numbers for your engine
http://www.briggsandstratton.com/maint_repair/manual_and_more/docsearch.aspx?mod...
I trust this will assist you  in making the correct replacement
Also your timing is out of correct firing order .
Easy way to set timing is this way.
1. with the magento flywheel at After magnet Both Valves should open slightly together
2. As the Flywheel turns intake opens fully and exahust is closed as the piston begins to travel up the intake closes and compression begins with firing as the magneto is at Top Center.
3. As the Magneto passes and the piston begins to tranvel down the exaust valve should open as the piston comes back up both valves open again.
Correct Timing.