Small Engines (Lawn Mowers, etc.): Briggs & Stratton 16 hp twin wont start, briggs stratton, wiring harness

Question
Briggs & Stratton Model 402707  Type 1205-01
1: It turns over good
2: new magneto and plugs(great spark at both plugs)
3:Compression is 75 psi on both cylinders
4:I can see gas coming into the intake.(I tried putting gas in the carburetor it won't run).
5: Spark plugs are dry.
6:I put gas directly into the cylinders it still will not run.
7: It will backfire occasionally.
What do you advise?

Answer
Sounds like something is goofed up with the timing.  Did the flywheel key shear part way some how?  I have seen a few of these, but not many throughout the years...cam problem perhaps? Check your flywheel key and let me know.  Good Luck...Don't give up we will figure it out!

One more thing, disconnect the ground wire from the wiring harness that attaches to the engine and try this too.  Perhaps we have an interlock issue that is preventing it to start.