Yeah, Yamaha's parts catalog calls those threaded rods that run through the engine somthing like "engine stud bolt" or "engine stud screw" or something like that. I've already priced replacing all four. They're the things holding front two sections of the engine onto the big gray thing housing the transmission and crank and they poke through the aluminum head. Well one of those snapped off right at the back, behind the cast iron portion of the engine, probably flush with the surface of the large gray housing.
I probably I can't get to it any other way than removing the cast iron section. Now, on mine, that iron block is pretty nappy looking, and it won't just slide off the bolts.
I'm trying to figure out if I need to do anything special, like try to remove all the studs or drain the tranny and remove the piston, shake a chicken foot at it while dancing around it in a circle, etc., or if I can just spray WD-40 on it, smack it just right, and pull it off.