REFLECTOR:Mag Timing Slipped?
dean fitzbag
reflector@tvbf.org
Mon, 9 Feb 2004 09:22:59 -0600
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That's about the degree of seperation from one bolt hole to another. =
Maybe, the reference point is misplaced do to the flange behind the prop =
being attached to the wrong bolt holes.=20
----- Original Message -----=20
From: Jim Sower<mailto:canarder@frontiernet.net>=20
To: reflector@tvbf.org<mailto:reflector@tvbf.org>=20
Sent: Monday, February 09, 2004 8:55 AM
Subject: Re: REFLECTOR:Mag Timing Slipped?
It's a puzzlement sure enough.=20
<... Is it reasonable to think that the points could wear enough to =
cause the timing to move that much ...>=20
The points don't wear measurably, but the rubbing block does. Rubbing =
block wear causes point gap to decrease, dwell to increase, timing to =
retard, so that wouldn't seem to be the problem.=20
Interesting phenomenon ... Be sure and let us know when you track it =
down ... Jim S.=20
Ronnie Brown wrote:=20
I am doing my first condition inspection on my 173 Elite RG and all =
is looking great except: When I checked my Slick mag timing, I found it =
at 32 degrees BTDC. Since our Cessna 172 in 10 years never had the =
timing reset except for the 500 hour mandatory inspections of the Bendix =
dual mag, this has me scratching my head. The timing on the Jeff Rose =
has not changed. The retaining bolts were tight, an internal inspection =
of the mag reveals nothing (however, I have not checked the internal =
timing yet) , and I KNOW the timing was set correctly (25 degrees BTDC) =
on this Lycoming IO360. I had a low static RPM - 2100 rpms - so we =
checked everything before changing the prop. Any worn parts in the =
gearing would cause the timing to be more retarded. Is it reasonable to =
think that the points could wear enough to cause the timing to move that =
much? Or any other ideas? THANKSRonnie Brown
--=20
Jim Sower ... Destiny's Plaything=20
Crossville, TN; Chapter 5=20
Long-EZ N83RT, Velocity N4095T=20
=20
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<DIV>
<DIV>That's about the degree of seperation from one bolt hole to=20
another. Maybe, the reference point is misplaced do to=20
the flange behind the prop being attached to the wrong bolt=20
holes. </DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style=3D"FONT: 10pt arial"><B>From:</B> <A=20
title=3Dmailto:canarder@frontiernet.net=20
href=3D"mailto:canarder@frontiernet.net">Jim Sower</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dmailto:reflector@tvbf.org=20
href=3D"mailto:reflector@tvbf.org">reflector@tvbf.org</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, February 09, 2004 =
8:55=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: REFLECTOR:Mag =
Timing=20
Slipped?</DIV>
<DIV><BR></DIV>It's a puzzlement sure enough. <BR><... Is it =
reasonable to=20
think that the points could wear enough to cause the timing to move =
that much=20
...> <BR>The points don't wear measurably, but the rubbing block=20
does. Rubbing block wear causes point gap to decrease, dwell to=20
increase, timing to retard, so that wouldn't seem to be the problem.=20
<BR>Interesting phenomenon ... Be sure and let us know when you track =
it down=20
... Jim S.=20
<P>Ronnie Brown wrote:=20
<BLOCKQUOTE TYPE=3D"CITE">
<STYLE></STYLE>
<FONT size=3D-1>I am doing my first condition inspection on my 173 =
Elite RG=20
and all is looking great except:</FONT> <FONT size=3D-1>When I =
checked my=20
Slick mag timing, I found it at 32 degrees BTDC. Since our =
Cessna 172=20
in 10 years never had the timing reset except for the 500 hour =
mandatory=20
inspections of the Bendix dual mag, this has me scratching my =
head. =20
The timing on the Jeff Rose has not changed.</FONT> <FONT =
size=3D-1>The=20
retaining bolts were tight, an internal inspection of the mag =
reveals=20
nothing (however, I have not checked the internal timing yet) , and =
I KNOW=20
the timing was set correctly (25 degrees BTDC) on this Lycoming =
IO360. =20
I had a low static RPM - 2100 rpms - so we checked everything before =
changing the prop. Any worn parts in the gearing would cause =
the=20
timing to be more retarded.</FONT> <FONT size=3D-1>Is it =
reasonable to=20
think that the points could wear enough to cause the timing to move =
that=20
much?</FONT> <FONT size=3D-1>Or any other =
ideas?</FONT> <FONT=20
size=3D-1>THANKS</FONT><FONT size=3D-1>Ronnie =
Brown</FONT></BLOCKQUOTE>
<P>-- <BR>Jim Sower ... Destiny's Plaything <BR>Crossville, TN; =
Chapter 5=20
<BR>Long-EZ N83RT, Velocity N4095T <BR> =20
</P></BLOCKQUOTE></DIV></BODY></HTML>
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