Maybe check float level. I've had trouble on other bikes when it's set too low; bike starves and dies when pointing up or downhill. Check your fuel filter and the one inside the tank too. May be fuel starving there too. And don't forget to check your tank breather. If the tank isn't taking in air as fuel is used, it will starve the carb sometimes.
Nice video and some of those tight sections looked like a lot of FUN!