John Deere Z225 blows smoke during start then quits

[spring creek]

Hello,
My machine just started to do this for no apparent reason. So it starts hard, finally catches for about 2-3 seconds, blows a lot of white/blue smoke then quits. I am stumped. Any help will be appreciated.
Thank you.

 

[spring creek]

Follow up: I was reading around the forum and saw some references to gas in the crankcase...well guess what? The crankcase was full of gas... So is this a carb kit or a head gasket fix and how would I tell? Or do just do both?
Thanks again for reading.

 

[Rivets]

Just replace the float needle and seat, plus float bowl gasket after a good cleaning and you should be good to go.