[Farmall] [AT] Never Heard Such a Bang!

[szabelsk at gdls.com]

One thing to consider is that you have a exhaust valve stuck open and you 
pushed a fuel mixture into the muffler when you cranked the engine. That 
might explain why the bang came from the muffler when the engine fired. 
Depending on how good the internals of the muffler were, you could have 
blown the baffles into pieces and now you have a plugged exhaust pipe at 
the manifold. Had a similar problem with a car once where the muffler 
baffles blew out and plugged everything up. Couldn't get the engine to 
start, let alone barely turn over due to back pressure in the muffler 
system. Try pulling the muffler off and looking inside of it, check the 
manifold for debris, and then try to start without the muffler installed.

Carl Szabelski

The Borg Are Wrong, Resistance Is Not Futile ..... It's Voltage / Current