BroJack wrote:

Run the 18 HP Cub Cadet 90 minutes, take a break for an hour, then the
Cub won't start, regardless of whether I use full choke, partial
choke, or no choke. Battery is OK. Next day, tractor starts fine, no
problems.

Is the engine still overheated after a one-hour rest? Any tips.

Thanx,
Jack
check and see if you are getting any fire(spark) from the spark plug
wire after it kills and wont start...that is where i would look first..
it might be the coil heating up and doing that...if thats OK then you
check the spark plug(a spark plug that is contaminated with deposits
will start up fine and glow when hot and act like its firing all the
time and not let the engine run at all.. once the engine cools down the
spark plug will cool down and act OK and the engine will run fine until
it heats up and do the same thing again.. we had a car back in the 50's
that did that once a week on our trip to the park.. my dads car would
conk out in the same spot each trip.. wait an hour and start right up..