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<DIV>I was having similar problems 2 years ago and finally resolved it by going
to a mixture control carb which worked very well. However, the problem
returned when I went to a new plane and did not want to use the mixture control
carb on a new setup with a new plane. I was able to resolve most of the
problem by lengthening the pipe in 1/2 inch increments until the transition
smoothed out. I resolved most of the problem but still had a some gurgle
in transition. I was running Magnum #1 and an APC 17x12. After some
conversation with Lance Van Nostrand (AeroSlave), he suggested I reduce the
compression somewhat by adding a head shim, or reduce the nitro to 15%. I
tried the head shim and my problems mostly disappeared. After
that, I went to an AeroSlave pipe and my problems went away completely. It
transitioned cleanly through out a flight and had a nice mellow sound, more than
plenty of power for a 9 3/4 pound plane. It runs very well on either 15%
or Mag #1 now.</DIV>
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<DIV>Every condition is different and I don't know if any of this will
help. I would suggest the 10% nitro might be a little light for the 16x14
prop. Have you tried any higher nitro?</DIV>
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<DIV>Don </DIV>
<DIV> </DIV>
<DIV>In a message dated 2/17/2006 6:28:55 P.M. Pacific Standard Time,
rharden1@cox.net writes:</DIV>
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<DIV><FONT face=Arial size=2>Hello All,</FONT></DIV>
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<DIV><FONT face=Arial size=2>I need some of your expertise. I am having
trouble with my OS 1.40 RX loading up in mid range. The engine has
5 flights and approx 2 gallons of fuel through it. I am
using an APC 16 x 14 prop, OS T-6010 Tuned Silencer, tried the A5,
#8 and type F plugs (no difference), Magnum fuel 10% nitro with caster/synth
blend, pipe set for 8000 rpm, and using the short needle valve.
The low end idle adjust screw is adjusted all the way to the lean (all the way
in) which is necessary to idle smoothly. Transition quickly from idle to
max throttle isn't too bad but slower than I would like. If
I set the throttle at 30% to 50% it loads up and and slows in
RPM. In transition from mid to high throttle
the engine vibrates and burbles for 3 -4 seconds before
it clears and comes on the pipe, it has even stopped running a few
times. I have read that some folks use the longer needle valve and
higher nitro to minimize this problem, but I haven't tried that yet.
From those of you who have experience with this, what is going on,
and what are my
options?</FONT></DIV></FONT></DIV><BR><BR>_______________________________________________<BR>NSRCA-discussion
mailing
list<BR>NSRCA-discussion@lists.nsrca.org<BR>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</FONT></BLOCKQUOTE></DIV>
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