Crank Pulley Tap size please

Hi, after many an hour I managed to eventually remove the crank pulley bolt after finding it bodged half in half out from the previous owner

Before I put everything back together again I'm wanting to clean the thread out inside the crankshaft as the bolt that was removed was a proper mess.

Does anyone know the correct tap size to do this? It looks like a M22 with 1.5mm pitch but Im not sure & don't want to bugger up the crank at this late stage!!

Cheers

Key

Hi, Key,
I'm sure you've got your info a long time ago now, but as I am a new recruit to Landyzone and saw your request when browsing this forum, I though I'd answer anyway. The thread is M20 X 1,5 mm pitch