Karl,

With the others out you might be able to get a good sized Vise Grip
pliers on it REALLY REALLY tight and give it a twist.  This tool can
work wonders if you can get a hard bite.  Alternatively, you might use a
Dremel grinder to flatten two sides and put a wrench on it.  You don't
want to risk drilling into the threads in the crank if you can avoid
it.  When the head isn't broken off there is hope!

Karl Wolz wrote:
>
> When I went to remove my flywheel today, I found that all of the hex bolts
> had been rounded a bit by the engine's previous owner.  I managed to get
> four of them out with no real problems (just hammered the wrench into the
> bolt head).  The last one was, and now is more of, a mess.  I had applied
> WD-40, tapped it with a hammer, and applied heat.  Any suggestions on what
> to do now?   I'm planning on drilling it out tomorrow.
>
> Thanks,
>
> Karl Wolz