I have been a little unwell over the past week, so no building, but all good now. I was not comfortable with the oil radiator fittings I had purchased last week. I have been told the oil radiator ports are 1/4" NPT threads and have also been told they are M14 threads. After purchasing 1/4" NPT elbows to AN8, I have decided they are incorrect and I needed M14 to AN8 adapters. The oil system is such a critical system and I need to ensure it is 100% correct. I could not find any M14 to AN8 elbows, so I ordered straight adapters. Much happier with the M14 straight adapters as apposed to the 1/4" NPT elbows. ( which I now have a small collection ).
PS. Finally found the reference !!!! Rotax 914 Installation Manual . Towards the end of " Lubrication System " section. Definitely M14 X 1.5