Small Engines (Lawn Mowers, etc.): lawn tractor wont start when warmed up, mtd lawn tractor, compression gauge

Question
I have an old mtd lawn tractor w/ b+s 14hp twin model 400700. It starts and runs well(for hours) until you shut it off then it does not want to start up again. I have fresh fuel w/ stabilizer, new spark plugs, and have checked for spark when it is not starting(it has spark and sometimes even starts to fire up with one plug out). I did adjust carb beginniing of the season but i usually do to get it running smooth. I installed a inline fuel shutoff and run the engine out of gas to shut it off to see if flooding is the problem. That works sometimes, but if it does not fire right up it seem like I have the same problem. You can also smell gas like the engine is flooded. If you let it sit for awhile it will start right up. Wondering if something in the carb is causing it to flood out. Hate to buy a $140 carb and it not be the problem. Could me turning screws to much for adjustment cause damage to carb? Any opinions would be appreciated.

Answer
Damage can occur to the carb if the needles are screwed in too much/too tight.

Have the valves ever been serviced?  Do you have a compression gauge or leak down tester to check engine compression.  Are the intake and head gaskets in good shape?  I've had leaky gaskets cause hard starting when hot.  A leak down tester work well for checking compression and identifing leaking gaskets.

Eric