I think I might have found the issue myself. When comparing the VTOL engines to the ION versions (ION lifts off ok) I realised that the only differance is from the weight of the fuel and when I looked at it in game the stock MK2 has a dry mass of 0.9 but when full of fuel it is over 20 tons... So I think something may need to be tweaked lol. It was trying to use your builds that got me to try the Eagle. I look forward to the Mun base and landing pad you mentioned. Edit: Ok now Im confused, every tank that takes the same kind of fuel weighs what its suppose to, like the Jumbo is 36 tons, X200-16 is 9 tons ect. So its not a issue with the fuel weight...