What is the bolt size required to mount this B&S engine? I tried M10 and it's not quite right. M8 definitely too small. Is it some sort of SAE size or odd thread?
If remember correct the Briggs are unthreaded to start with they are 3/8 holes that they use self tappers. So if the new and never had screws in it then you just tapped to which 3/8 course thread that is easily available in your area provide you have the correct tap.