Yes... it has nothing to do with 'vapor lock'.
(nor spark plug gap change from the heat)
Its a 'fuel to air' ratio problem... (too much fuel to the air).
You shouldn't use any choke in hot weather... and... did you try opening the throttle ?.. (let more air in)
Unless the ped is jetted wrong (or worn out with low compression) ... it will start in hot weather.
I can ride my PA 30 miles in 90 degree heat.. let it sit for 5 minutes .. (which makes the carb even hotter)... and it fires off with a 3 step push... just like when cool.
alan.. if there is an airbox lid (leading to the carb) you can remove during the heat of summer... do that... and put it back on when the weather cools off.