Dale Rogers <rogersda@cox.net> wrote:

"""
   Tap it out with a pipe thread and put a pipe plug in
 it.  It would be a good idea to remove the housing from
 the engine, first.  8)
 
   Oh! And remember, pipe threads are _tapered_ - don't
 run the tap in too deep.
"""

The trick to achieving proper thread depth with a tapered pipe tap is to have 5-7 threads showing on the tap (above or outside the hole) when you're done. I've marked all my pipe taps with a ring of nail polish at thread 6 down from the driven end as an indicator.  Works great.

    <Marv>