What size box spanner/long socket to extract Injectors?

[Muddy32]

Beta 13.5HP engine. and away from the boat. But I know what I have down there is not big enough. 17mm to detach piping but what about the main body?

 

[earlybird]

I can't tell you the size, but Beta are very helpful with that type of information over the 'phone. You get to speak to a proper "hand-on" person, (provided they're open tomorrow!)
Whatever it is, it'll probably need to be an extra deep one, and they can be tight.