Small Engines (Lawn Mowers, etc.): Kawasaki will not start, puff of smoke, new spark

Question
I have a Model FB-460VAS21. The coil is good,ignighter is good,new spark plug,cleaned carb and it still has no signs of starting besides a puff of smoke coming from carb.Could this possibly be a valve problem and if it is how difficult is replacing the valves?

Answer
Will the engine start if you use starting fluid sprayed directly into the carburetor though air filter housing?
If so, then the valves, ignition, timing and compression are working.  That leaves the fuel system, aka, the carb.
Let me know what happens with the starting fluid.
Eric