Do they sell special bike tires for people over 300 pounds?

Question

i like to ride, but my tire seems to have a "pinch flat"

Answer 1

Just go with a larger size.  I run 700x 28s on my tandem.  Combined weight of 360 pounds.  In 6 years have only experienced a couple of pinch flats.  I air up the tires each time I ride.  I run the maximum listed on sidewall.  I carry two spare tube, patch kit, and a spare folding tire.  

Try running 700 x 32s.  Should work OK.  

Flats are a bit of a drag.