Thanks for the reply's everyone.

Dave - I haven't used anything on the pickup. It's just open tube. What I will do is use the filter that comes with the UF and see how that goes.
Maybe it's obvious that this is the issue. Thanks for the feedback.

DelGatoGrande- I don't think its a main tank issue as there is very little air in the header on landing. I do however like your home made pickup. Nice!!

RobinLeblond - An open fill like in this kind of system would result in a flame out shortly after take off. There could however be a leak in the fill like but I don't think so. The plumbing is pretty solid.

Dr Honda - I will give the felt filter a go. Never had a problem with commercial headers. You may ask why I am not using one then

Mr Matt - That has to be the issue. I would have thought a slow roll would have been pretty gentle of everything and allowed the bubble to roll around the outside of the tank.. I guess not.

Boomerang1 - I will put the felt filter on and report back.

​​​​​​​Paul.