Need to Chase studs on Steering Bracket - HELP

[fishfun83]

I need to re thread the two studs that are screwed into the Steering Bracket on my C80TLRV Yamaha outboard. Over time, the two nuts have backed off and there is about 3/8 inch play. The studs and nuts are rusted badly and if I can't remove the old nuts and chase the existing stud threads, I am going to have to remove the engine and replace the entire Steering Bracket Assembly. The Yamaha part number for the nuts is 90185-10051-00 and the part number for the studs is 90116-10175-00.

Can someone please tell me what size nut or stud this is so I can use the proper size die.

[boats.net]

I think they are 10mm but not sure what thread, probably .125

[bumperfood]

I don't know your motor, but, would there be enough threads still usable to allow you to be able to use the old nuts, and a spacer(washer etc,), if unable to chase the thread?