Volvo Penta With Outdrive No Reverse

Hi Folks,
Just been out on my mates Fairline Sprint 21, everthing ok at first, then lost drive, revs up but no drive. Investigation revealed no fluid in reservoir, topped up and after a couple of rev ups it suddenly banged into forward drive, then discovered reverse & neutral positions engage forward as well, in other words were stuck in forward drive. Tried everything we can think of, but it will only go forwards. Can't see any obvious way of bleeding the system, so guess it must be mechanical.
Has anyboby had this problem or have any idea for a fix.
Help would be much appreciated.
Cheers, Steve.

 

Stuck in forward drive sorted

Hello all who have looked.
Traced problem to a failed split pin in final linkage to out drive.
So were off at full speed now, whoooopeee!!!!!!!!!!!!!!!!!!!