Unscrewing 1" exhaust pipe from Kohler engine bolck

[ronhatch 406]

What is the best and safest why to remove the 1' stub pipe from a cast-iron K-241 Kohler block? 
 

[KC9KAS 4,744]

Lots and lots of penetrating oil 1st. Let it soak.
Use a pipe wrench or good channel lock pliers.
If it is broke off already, use a hacksaw blade to make a relief cut and a small punch/chisel to bend one side of the cut pipe up. At this point, you should be able to use a needle nose plies to remove the stub.
I always use a pipe tap to clean up the threads once the pipe stub is removed.

Another method...heat it up with a torch, melt some wax onto/into the threads....use a pipe wrench/channel locks to remove the stub.
This method also works with a large "easy-out". Just be careful to NOT drive the easy out into the block!

[clip 185]

If you don't have a pipe tap, take a cut-off wheel or hacksaw and cut a vertical slot down the threads in a new 1" pipe nipple, then screw this in like you were tapping a hole. Half to one turn forward, quarter turn back, using cutting oil. It'll act like a pipe tap to clean the threads. Not as elegant, but it'll do in a pinch.