"Orval Fairbairn" wrote in message
news
In article ,
"Travis Marlatte" wrote:

"Peter Dohm" wrote in message
...
Right magneto is "hot" (ungrounded). The "OFF" position grounds
both
mags.


I know from personal experience that a lot of pilots continue to have
serious misconceptions about such things, but it still bothers me.
This
is
the sort of thing that is part of every run-up, and therefore should
have
been part of the aircraft systems knowledge requirement to get the
license--not necessarily the grounding issue, but which magneto
actually
fires its set of plugs.



I don't get the connection. Why would the licenced pilot need to know
which
mag and which set of plugs is firing on Left or Right key position? Know
why
the mag check is important and what to watch for during the mag check,
yes.

So you can tell which mag has the problem -- ehether it is plugs,
harness or the magneto itself. Sometimes it is just a fouled plug; other
times it is a dirty cigarette; other times it is a loose harness
connection. Learn it and use it!


You and Peter seem pretty set on this and I don't quite understand why.
Here's two scenarios I'm thinking about:

1) I do a mag check and notice that I don't get an RPM drop on the Left (or
Right) position. So I taxi over to the garage and I say to the guy, I says,
"Say! I think I may have a broken P-lead. Do you have time to fix it while I
go get some lunch?"

2) I do a mag check and notice that the engine runs rough on the Left (or
Right) position. So I taxi over to the garage and I say to the guy, I says,
"Say! I think I may have a fouled plug that I couldn't clear with leaning.
Do you have time to fix it while I go get some lunch?"

Now, if I happened to be out on a lake somewhere and had a fouled plug that
wouldn't clear, I'd walk over to my tackle box, see, and pull out the green,
spotted jitter bug. 'Cause when I'm desperate for dinner, that's what I
always use. In the morning, I'd pull all four of the lower plugs because by
the time I translated left or right for top or bottom on the left or right
side, I'd... well, I'd rather be fishing and, chances are, it's one of the
lower plugs.

-------------------------------
Travis
Lake N3094P
PWK