Turn out your highs speed carb screws out a little. Sounds like your getting lean hesitation. A ski, when running too lean will hesitate and even at times cut out.
Check that out, if thats all good your carbs may not be getting all the fuel they need. Check fuel lines, filters, internal carb filters ect...
This is a problem I'd address instantly instead of ignore, your engine depends on it. Otherwise you maybe doing an expensive rebuilt in the near future.