When the previous owner changed the carb to one that ddnt need a return fuel line he left the hose where it was near the inlet manifold and just blanked it off with a bolt in the end. Is this adequate or should this terminate in a one way valve. Theres a Newton filler cap on the tank, not sure if these are vented.

It a simple law of physics that as tank empties, fuel has to be replaced by the same volume of air and that air has to get in from somewhere hence the vent wherever it may be ....pressurized tanks are different of course ie lpg produces its own pressure to feed the engine by its change of state liquid to gas.

I have a breather on the filler neck but also got kev to put one on the tank. I've put a one way valve on the tank and blanked the filler connection off with a stainless bolt.
Will this be ok for iva ect. I feel it's suitable but will others think otherwise?