bobcat 773 nock or exhaust leak

[Ryan]

Iam looking at a machine that has what sounds like a exhaust leak. How can I tell if it is maybe out of the manifold or internal. If manifold has anybody ever replaced on and if so what kind of job is this? Thanks Ryan

 

[Tazza]

I recently found i had a leak on mine, my battery was low and i got my girlfriend to start the machine while i was around the back with a jumper pack on the battery. When it starts from cold, i saw a puff of black smoke come from the flexible joint from the exhaust manifod to the muffler.
Can you try looking for it this way? There isn't much in the way of tubing from the engine to the muffler and should be easy to spot.