Check out this flywheel mishap. I know it wasn't welded just turning too fast but the oomph is still there...Bob
http://gardentractorpullingtips.com/flywheelbreakage/flybreak.htm
how meany RPM is it going to have to do ?
if its on an old thumper i cant see it been much of a problem if its doing 10Krpm things are a bit diffrent
as said a picture of it . size and how many rpm its dong will be the governing factor as to how and if repair is an option given that its a restoration projectObviouslt catasthrophic....but why did it fail
There could be a thousand reasons
We need the OP to post more detail otherwise we are speculating without much info