[Joshua May]

If I understand you correctly, then this should work. I can't remember the exact two-joystick code, but this concept should be valid.

if (p1_sw_top)
{
  pwm01 = p1_y + 4;
  pwm02 = p2_y + 4;
}
if (pwm01 > 138)
  pwm01 = 138;
if (pwm02 > 138)
  pwm02 = 138;