Well of course it could be lots of things. Hopefully just a carb' problem. Could be a spark plug problem as well. Assuming that it has been warmed up sufficiently, I've had similar 2 stroke response with bad crank shaft seals. Starts and runs fine until you give some gas and the crankcase pressure goes up, then the intake charge starts blowing out the seals. Other than my weed eater, my 2 stroke experience is all from the '70s and none of it involved liquid cooling. I've no experience with RC valves, but if I understand the
Wiki' explanation correctly then I don't think it would cause a bog, although it would effect performance at lower RPM.
Sounds like you're going to be the Father-in-Law we all dreamed of getting someday.