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<DIV><FONT face=Arial size=2>In looking at this failure it appeared at first the
bottom half of the conrod wrist pin bushing was worn, thus an egg shaped hole.
At least that would make sense to me. However that isn't the case, the bushing
ID is round, so the wear seems to be to the entire bushing. I'm beginning
to believe the bushing to wrist pin fit was a tad loose from the factory or
the finish on the bushing bore was poorly done and from normal running the
bushing wore out to the point it affected performance in a big way. If the wrist
pin finish was "aggressive" the piston bores would be worn which is not the
case. In any event, once I receive the new conrod I'll improve the oiling for
the wrist pin. </FONT></DIV>
<DIV><FONT face=Arial size=2>Hmmm, 2- ST2300's are approximately $400, 'bout the
same as one OS 140 or Webra 145. Still a good value for an 11lb airplane.
</FONT></DIV>
<DIV><FONT face=Arial size=2>No Ron, the OS and ST rods are different <G>
but it appears the rear bearings on both engines are the same. I happen to have
a couple of SS rear bearings in stock for my RX....</FONT></DIV>
<DIV><FONT face=Arial size=2>Ed M.</FONT></DIV>
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<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=ronlock@comcast.net href="mailto:ronlock@comcast.net">ronlock</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, June 24, 2003 6:48
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: ST2300 conrod, wrist pin
end</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Ed, Maybe an OS 140RX rod would fit, they
are "only" $34.99. <G></FONT></DIV>
<DIV><FONT face=Arial size=2>Ron Lockhart</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=edbon85@optonline.net href="mailto:edbon85@optonline.net">Ed
Miller</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, June 23, 2003 11:37
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: ST2300 conrod, wrist pin
end</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Oh sure, Tower will gladly sell me a new conrod
for the bargain price of $39.99. That's even a bigger theft than YS parts :
)</FONT></DIV>
<DIV><FONT face=Arial size=2>Ed M.</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=emorydmd@earthlink.net href="mailto:emorydmd@earthlink.net">Emory
Schroeter</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=edbon85@optonline.net
href="mailto:edbon85@optonline.net">edbon85@optonline.net</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, June 23, 2003 10:56
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: ST2300 conrod, wrist pin
end</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Nope. I haven't had that problem. Can you get
a replacement part?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Emory Schroeter</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=edbon85@optonline.net href="mailto:edbon85@optonline.net">Ed
Miller</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, June 23, 2003 10:41
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> ST2300 conrod, wrist pin
end</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Any of you folks out there that have been
running ST2300's ever experience a short lived wrist pin end of the con
rod ?? I have approximately 100 flights on a ST2300 in a Hanson Dalotel
spinning an APC 18x8 with S&W fuels 20% to 30% nitro ( 20% oil in
all fuels ) and the bushing in the wrist pin end of the con rod is worn
out. I'd say there is at least .030" clearance, maybe more. Engine was
down about 700rpm on the ground and never really settled on a
rpm and acted lean in the air, in verticals it went flat, would no
longer haul plane vertically indefinately. This all happened in maybe 5
or 6 flights, went from a powerhouse to a dog. There is only one small
hole in the top of the conrod to lube the wrist pin ( approx .040" in
dia. ), the wrist pin is fine and measures no wear at all where the
conrod rides on it. I'm going to order a new conrod, if the new one only
has one hole in it I may enlarge it a bit as well as add a second hole
from the bottom of the wrist pin boss on the rod. Luckily I have a 2nd
ST2300, just installed it and I'm back to 8800 rpm on 25% nitro with the
18x8 so I'm ready for the Pocono pattern contest. Both my ST2300's are
Italian made, the only notable difference is one has a longer crankshaft
( prop end ).</FONT></DIV>
<DIV><FONT face=Arial size=2>Thanks...Ed
M.</FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>