Hi,
I need to fit an oil pressure guage 0n my 919 blade engine, which means fitting a t piece where the switch is now.
Does anyone know the thread size?

The thread is M10 x 1.5 but it might be easier to remove the boss that it screws into and retap it 1/8 npt as most of the aftermarket senders use this. The boss can be removed from the main oil gallery using a 17mm socket but it is real tight usually. Be creful when refitting the boss as it is M2o fine and easily cross theaded.
regards
Andy

Thanks for the help and advice Andy.

Are you sure it's 1.5 and not 1.0.
Sorry to doubt you but i have been looking for adapters and can't find any in 1.5.