Shattered Stud - Engine rebuild?

I guess this might be kind of obvious... I just noticed a small but steady oil leak on a fin of the cylinder block. I traced it back to an engine stud, and found that it has a massive split running straight through it. So I guess I'll be taking the engine apart and rebuilding it this winter?

 

Or just replacing the stud, depending on which one it is.

Don't take one of these motors apart lightly-- "rebuild" parts aren't that easy to come by and it's easy to paint yourself into a corner, cost-effectiveness wise.

Better to research, diagnose, and weigh your options.

 

Because Yamaha built these bikes as economically as possible during the production run; everywhere they could save money, to maximize profit was implemented.

Inexpensive, soft-steel fasteners.
Untreated studs and bolts of incompatible materials which seize.

Dealing with the fastener seizure issue makes performing maintenance and repairs, which should be a trouble-free matter of removal and replacement of parts and assemblies.

But, the process is often rendered quite complicated when a Screw, Nut, Stud or Bolt is frozen solid. Seized. Breaking-off before breaking free.
Requiring detours, adding hours, costing more than expected or completely ruining a restoration.

 

Hey thanks for the response! It's the furthest most front left stud that runs partially outside the cylinder block, at the back of the fins. I'm watching a piece of that stud flex when gently tapped with a pen, so I don't expect it to come out the easy way, in one piece through the top.

Is it even possible to get intact studs out without pulling off the head and block first?

I just finished getting all of the seized intake manifold screws out, so can totally appreciate the economy of some of the factory fasteners on these bikes. Getting into the engine isn't a project or expense I'm excited about at all, but figured ignoring it isn't a safe idea either.