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<DIV>If you have your engine leaking it is because the engine has a leak,
orings, <BR>gaskets or the likes. On the DZ engine you can to some extent
overcome this <BR>issue by richening the pump a bit, however the leaks will
always get worse <BR>and worse. The black plastic check valve could be a source
if you have <BR>removed the little black clip that hold the fuel line to the
intake tube. <BR>The fuel line will pull on that check valve and cause it to
wobble at its <BR>base. Next thing is intake tube o-rings, valve cover gasket,
and front <BR>pushrod tube o-rings are next in line. A super rich pump setting
can spit <BR>from the carb intake " air valve" with excess oil that is in the
bottom of <BR>the engine. I have also seen loose head bolts cause this issue. If
you have <BR>an issue with the head bolts coming loose, replace the head gasket
with a <BR>new one and then tighten the head properly.<BR><BR>To solve the leaks
replace the o-rings and or gaskets clean everything with <BR>denatured alcohol
and re-assemble with both parts clean and dry. In some <BR>cases a small amount
of alcohol will help lube the o-ring as it seats...but <BR>do not install with
any oil. Do not use rubbing alcohol for this as it <BR>contains some water
content. Denatured alky is the stuff to use. You can <BR>make them absolutely
dry as a bone doing this.<BR><BR>This issue can be masked if you have a leak in
your header to pipe <BR>connection as addressed ina previous email.<BR><BR>Troy
Newman<BR></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=troy_newman@msn.com href="mailto:troy_newman@msn.com">Troy A.
Newman</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, December 11, 2007 12:20
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Hatori
Short Pipe O-Rings</DIV>
<DIV><BR></DIV>
<DIV><FONT size=2>Jim,</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>the NMP replacement viton o-ring is sized to accept the NMP
header NOT the Hatori header. The Hatori is 15mm and the NMP is 5/8" the
difference between the or-rings is about 3.5-4 thousands on the ID. This will
be enough to cause it to leak.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>If you are using the Hatori header you need to replace the
o-ring with the Hatori original o-rings. And yes 50-75 flights is normal
replacement time frame. The Hatori original replacements are available from
Central Hobbies.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Proper cooling on your engine and exhaust system will extend
the life of the o-ring, improper cooling and abuse will eat the o-ring in as
little as 5-10 flights.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>The NMP o-ring replacement for the NMP header is a much more
robust material than the Hatori Original. The Viton material on the NMP will
tend to last quite a bit longer than the Hatori originals. I have models
using both the NMP header with the replacement o-ring to fit that header and
the Hatori header-and o-ring versions. I can get about 50% better life out of
the NMP header/NMP o-ring version. I think it has to do with the cooling
properties of the NMP header. </FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I have been running the replacement o-rings for several
years.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Troy Newman</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=jim.woodward@baesystems.com
href="mailto:jim.woodward@baesystems.com">Woodward, Jim</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, December 11, 2007 11:49
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [NSRCA-discussion] Hatori
Short Pipe O-Rings</DIV>
<DIV><BR></DIV>
<DIV><FONT size=2>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Hi
Guys,<O:P></O:P></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><O:P></O:P></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">What is the final verdict on
these O-rings? Will a warm run “melt” the O-ring? Does the viton
replacement fit tight enough over the header? Recently my plane is
getting really messy, where as before there wasn’t a drop of burnt fuel
ahead of the exhaust stinger. I replaced the o-ring but still had the
mess. I pull the motor last night and checked out everything and the
motor looks great, bolts were tight, with no indication of any leakage from
the motor or header to motor/flange attachment.
<O:P></O:P></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><O:P></O:P></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I am using the Nishioka spring
clamp mount. All things considered and experienced, I think I prefer
the stock Hatori mount that comes with the pipe. The Nishioka seems to
allow for more fore and aft pipe slippage during running due to the thin
vertical white plastic supports (checked while running the plane upside down
to try and determine spray pattern and such - in which I didn’t find
one, which leads me to believe that it starts to happen maybe later in the
flight or heat cycle, versus the small amount of running I did as a cursory
check.<O:P></O:P></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><O:P></O:P></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Thanks,</SPAN></FONT><O:P></O:P></P>
<P class=MsoNormal><ST1:PERSONNAME w:st="on"><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Jim</SPAN></FONT></ST1:PERSONNAME><O:P></O:P></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><O:P></O:P></SPAN></FONT></P></DIV></FONT></DIV>
<DIV><FONT color=black><SPAN
style="FONT-SIZE: 12pt; COLOR: black; FONT-FAMILY: Arial"><FONT
face="Times New Roman"><FONT size=2></FONT></FONT></SPAN></FONT> </DIV>
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