Is any part of your fuel load above the jet in the spray bar?
Because from what I have just seen in the videos you have a control wedge tank mounted vertically and if it is full of fuel then the head will be above the jet.
This might cause the engine to sputter on a rich setting.
Check the PAW web site and it will tell you to never place any of the fuel load above the jet - perhaps this is the cause of the misfire?
I suggest in laying the tank flat and well under the spraybar and try again.
(And yes I have changed my log in details if anyone notices and will get Hobbsy to delete my old account.)
And I agree with the prop load being too high, the 11x8 is the recommended prop for the PAW 40 and a 11x5 should be much better.
Cheers.