XSeries-forum

so it's service time again and remembering the pain I had with the air filter housing can somebody confirm he allen key size. I'm sure its 5mm. I'm about to order a 14" key to get at that bolt at the back of the engine. I managed to somehow squeeze the last one in as we could not get that last bolt out. Don't want to damage the box this time round.
Any recommendations for keys would we most welcome. No flexi ones please.
Thanks.

7mm i think but sure somebody will be along soon to confirm or correct.