Kawasaki FR691V won't start - HELP!

I have a zero-turn mower with a Kawasaki FR631V that stopped running while mowing and won't restart.
 
TROUBLESHOOTING - Fuel, air, and spark right?  OH - and timing and compression too.
 
Fuel- all seemed well but we went ahead and replaced the fuel line, filter, and carb.
Air - brand new air filter, intake is clear
Spark - brand new battery, plugs and coils
 
Here is where it get's interesting ....
 
Timing - did find the woodruff key sheared, thought AHA!  The flywheel was 30-40 degrees off. Replaced the key and it still won't start.
Compression - tests at 80lbs, both cylinders equally.
 
I decided to check the valves, so I drained the oil, pulled the valve covers and heads.  No issues that I can see (broken parts) but there is a LOT of carbon built up.  Top end was cleaned when a bent push rod was replaced last fall.
 
QUESTION 1:  What should I look for as to the cause of the carbon before I put the motor back together?
QUESTION 2: Why won't it start?
 
I am at a loss on this one, any help you can give is appreciated!
 
-Jim

I gather it's carbureted? - YES
 
Pull spark plugs, attach to leads and ground to head. Have someone crank the engine and visually 
look for spark.  Just cause it's new, doesn't mean it's good. - ALREADY DID, GOOD SPARK
 
Should you have spark, try spraying some carb cleaner/starting fluid down the carb throat and see if it starts up/kicks for a couple of seconds.. - DID THAT TOO, WON'T FIRE ON STARTING FLUID EITHER
 
You mentioned the valves, did you check clearances on them?  - NOT YET
 
Has the machine been using up oil? - USING?  DUNNO.  I THINK IT IS LEAKING THOUGH.  THERE IS A RESIDUE AROUND THE BASE ON THE MOWER