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<DIV dir=ltr align=left><SPAN class=249350615-19042005><FONT face=Arial
color=#0000ff size=2>Thanks again Wayne...:) Very well spoken, clear, and
concise 2-stroke tuning methodology.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=249350615-19042005><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=249350615-19042005><FONT face=Arial
color=#0000ff size=2>Richard</FONT></SPAN></DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> discussion-request@nsrca.org
[mailto:discussion-request@nsrca.org] <B>On Behalf Of </B>Wayne
Galligan<BR><B>Sent:</B> Tuesday, April 19, 2005 9:12 AM<BR><B>To:</B>
discussion@nsrca.org<BR><B>Subject:</B> Re: OS mixture
question<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV><FONT face=Arial size=2>I helped a guy with the a similar issue this
weekend on his Mintor. Way too lean on the bottom end. His
would pop on acceleration or die coming out of the outside loop.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>For the OS 1.40 RX Try this:</FONT></DIV>
<DIV><FONT face=Arial size=2>Use an OS "F" plug.</FONT></DIV>
<DIV><FONT face=Arial size=2>15% nitro</FONT></DIV>
<DIV><FONT face=Arial size=2>I have not had to adjust the pump on any of the
OS's I have set up to date.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Set the top end till it peaks in rpm(use a
tach if you have one) and back off one click to the rich
side.</FONT></DIV>
<DIV><FONT face=Arial size=2>Bring it down to an idle and try to set
the idle</FONT> <FONT face=Arial size=2>to about 18-1900 rpm.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Let the engine idle for at least 20-30 seconds and
do not touch the throttle.</FONT></DIV>
<DIV><FONT face=Arial size=2> 1. if it speeds up or surges at
any time during this time the bottom end is lean.</FONT></DIV>
<DIV><FONT face=Arial size=2> 2. if the engine gradually slows
down and dies...its rich.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Advance the throttle with medium speed and
observe:</FONT></DIV>
<DIV><FONT face=Arial size=2> 1. if it burbles and picks up
speed or burbles and dies bottom end is too rich.</FONT></DIV>
<DIV><FONT face=Arial size=2> 2. if it falls flat or hesitates
then accelerates or dies it is lean</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>This may take several tries to get but once its
set then its just minor top end adjustments depending on weather
conditions.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Changing pipe lengths will also effect the low end
transition. A longer pipe setting will allow you to set the bottom
end a little richer and give better downline braking.</FONT></DIV>
<DIV><FONT face=Arial size=2>I find that running the bottom end as rich as
possible with out it loading up gives the best downline
deceleration.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Setting your pipe is a whole other
story. My best method is on a test stand. Set the pipe
long and run engine, tach the top end at peak rpm.</FONT></DIV>
<DIV><FONT face=Arial size=2>Shorten the coupler or pipe about 1/4" at a time
and observe the peak rpm. It will increase with each shortening of
the pipe. </FONT></DIV>
<DIV><FONT face=Arial size=2>Once it peaks in rpm or no longer increases or
drops in rpm this is the top tuning spot for your engine and pipe for max
rpm(not really the desired tuning).</FONT></DIV>
<DIV><FONT face=Arial size=2>At this point back the pipe off about 3/8 to
1/2". This will give you a good starting point. I usually
lengthen the pipe if I go to a higher loaded prop or</FONT></DIV>
<DIV><FONT face=Arial size=2>shorten it with a lighter loaded prop.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The OS 1.40 is a very predictable
engine. If it starts to load up and stall in the midrange for no
apparent reason or drops rpms
<DIV><FONT face=Arial size=2>after the glow plug is removed </FONT>first check
the plug </FONT><FONT face=Arial size=2>. </FONT><FONT face=Arial size=2>If it
continues to do the same thing then the bearing is probably on its way
out.</FONT></DIV>
<DIV><FONT face=Arial size=2>Replace the bearing with a sealed bearing or a
stainless steel bearing that goes in the EFI version. I have about
200 flights on one</FONT></DIV>
<DIV><FONT face=Arial size=2>of my OS's that has the sealed std
steel bearing from Bearings Limited in it and it is still going
strong. Another way to check the bearing is move the prop by the
tips</FONT></DIV>
<DIV><FONT face=Arial size=2>perpendicular to the engine and if you can feel end
play the bearing is getting loose. </FONT></DIV></DIV>
<DIV><FONT face=Arial size=2><BR>Wayne Galligan</FONT></DIV>
<BLOCKQUOTE dir=ltr
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=kurt@bozarthhomes.com href="mailto:kurt@bozarthhomes.com">Kurt
Bozarth</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, April 18, 2005 7:22
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> OS mixture question</DIV>
<DIV><FONT face=Arial size=2></FONT><FONT face=Arial size=2></FONT><BR></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">OS 140 RX (non-EFI)
question:</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">When I advance the throttle, the
rpms remain at idle for approx. one second, “pop” and then advance to full
throttle rpms I am not quite sure if this “pop” and hesitation is a
result of having too lean of an idle mixture or too rich. This is an
older motor released back when Hobby Services offered a free needle valve
assembly replacement to correct for mid-range richness issues. I do not
know if this was done or not – something I will check for tonight. I
have never adjusted the pump setting. Let me know your thoughts.
Thank you.</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Kurt Bozarth
</SPAN></FONT></P></DIV></BLOCKQUOTE></BODY></HTML>