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<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=990502921-05032006>Yeah, I tend to agree with Nat here. After some
discussion about the Perry loop idea, I know someone who actually tried it.
It came down to the theory vs. reality thing i.e. "only one way to find out..."
It seemed like a good idea, but it didn't seem to work on our big motors. I
think that in order for this to work properly, you would need a pump that is
capable of way more volume AND pressure than you need. In addition to this, the
regulator should be an external device, not inside the pump like the way it is
with a VP-30, or the internal regualtor needs to have an eaxternal "return"
line. This is how a fuel-injected automotive system works, so it is possible.
The Perry loop thing works for R/C cars and smaller motors but I think the
pump needs more volume to feed our big motors with that big gaping "hole" in the
system (the return loop). Maybe tuning the size of the return loop with a
restrictor would be worth a try. Is it worth the effort? Generally a VP-30 that
is properly adjusted will give reliable performance with just a vent line and no
tank pressure / no return loop. Props have a big effect on what happens when you
return to idle too. If you want to help downline braking, look at props before
you spend a lot of time re-designing the fuel system. Also, try setting the idle
a little bit richer. The slow transition to idle condition is sometimes
aggravated by a lean idle mixture. Not trying to discredit anyone's
theories, just passing along some of my observations.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=990502921-05032006></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=990502921-05032006>
<P><FONT size=2>John Pavlick<BR><A href="http://www.idseng.com/"
target=_blank>http://www.idseng.com</A><BR> </FONT>
</P></SPAN></FONT></DIV>
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<DIV align=left class=OutlookMessageHeader dir=ltr><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org]<B>On Behalf Of </B>Nat
Penton<BR><B>Sent:</B> Sunday, March 05, 2006 3:48 PM<BR><B>To:</B> NSRCA
Mailing List<BR><B>Subject:</B> Re: [NSRCA-discussion] Fuel Regulation in 2C
Engines<BR><BR></DIV></FONT>
<DIV><FONT face=Arial size=2>Diaphram operated fuel pumps made by OS ( Hanno,
140 RX, 91 SH <Perry?>) are self regulating in that output is
proportional to RPM, proportional to need. These pumps can be adapted to any
90 to 160 two stroke with JB Weld and without maching skills. The tank is
vented and there is no pressure in the system.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I have had impeccable performance using these
pumps on the OS91FX for the last four years. I believe the logic in the
circulating systems is
flawed.
Nat</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 href="mailto:vicenterc@comcast.net"
title=vicenterc@comcast.net>vicenterc@comcast.net</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
href="mailto:nsrca-discussion@lists.nsrca.org"
title=nsrca-discussion@lists.nsrca.org>NSRCA Mailing List</A> ; <A
href="mailto:nsrca-discussion@lists.nsrca.org"
title=nsrca-discussion@lists.nsrca.org>NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, March 05, 2006 12:22
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Fuel
Regulation in 2C Engines</DIV>
<DIV><BR></DIV>
<DIV>Hi Brian,</DIV>
<DIV> </DIV>
<DIV>You got it right. In the OS 160 we would like to set up the
pressure in the header before the carb as close as possible to the original
design (muffler pressure with tank close to firewall). In this way,
the carburetor metering system will work as was originally designed. I
will be doing some test and see what will work better. </DIV>
<DIV> </DIV>
<DIV>The expert at Perry recommended to send the overflow to the
tank. However, I agree that loop around the fuel pump could work since
that is one old method to control pressure in industrial pumps. </DIV>
<DIV> </DIV>
<DIV>Vicente</DIV>
<DIV> </DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #1010ff 2px solid; MARGIN-LEFT: 5px; PADDING-LEFT: 5px">--------------
Original message -------------- <BR>From: brian young
<brian_w_young@yahoo.com> <BR>
<DIV>So I guess the thinking behind doing this is that you deliver
the fuel to the carb and its there for the carb to take. But the fuel at
the carb nipple will only be under atmospheric pressure (since the tanks
vented), anything extra is free to go back to the tank. The venturi affect
of the carb will draw the fuel into the carb. I dont see why you would
need to go clear back to the tank, just loop around the pump. </DIV>
<DIV> </DIV>
<DIV>This sounds like it could take the variability of pumps out of the
equation and at the same time let the pump deliver fuel to the carb, but
not push fuel into the carb.</DIV>
<DIV> </DIV>
<DIV>Interesting.<BR><BR><B><I>Wayne Galligan
<wgalligan@texasairnet.com></I></B> wrote:</DIV>
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<DIV><FONT face=Arial size=2>Vincent,</FONT></DIV>
<DIV>! <FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I wonder if this "T" setup would work on an
OS 1.40. I already use the check valve in the vent so a couple of
"T's" and maybe I would be in business. Would you have to change
the pump pressure?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Wayne Galligan</FONT></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A href="mailto:vicenterc@comcast.net"
title=vicenterc@comcast.net>vicenterc@comcast.net</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
href="mailto:nsrca-discussion@lists.nsrca.org"
title=nsrca-discussion@lists.nsrca.org>nsrca-discussion@lists.nsrca.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent! :</B> Sunday, March 05, 2006
8:19 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [NSRCA-discussion] Fuel
Regulation in 2C Engines</DIV>
<DIV><BR></DIV>
<DIV>
<DIV>
<DIV>Good morning all,</DIV>
<DIV> </DIV>
<DIV>I have been using the OS 160, OS 140 RX and Mintor 140 with good
results in the last 4-5 years. We have been comparing and
discussing the advantages of YS compared with 2C. One of
the main advantages of YS is that in transition when power down the
engine goes instantly to 2000 RPM or less. The 2C engines always
takes too much time to get down to idle and I believe that causes us
(in pattern) some problems. </DIV>
<DIV> </DIV>
<DIV>I have been thinking that the problem is that the carburetor and
or fuel system that can not regulate properly (pressure or
flow). I think in these engines, the pumps are set to deliver
fuel at full flow (or pressure) without any regulation system
(like the YS). ! I had the opportunity to discuss this issue
with Perry Pump and they recommended to install a by-pass line.
The idea is to send the excess fuel (pressure) back to the tank during
transition. Perry Pump recommended to install the T as close as
possible to the carburetor needle valve. Also in their web site
they have an idea that he said is used for cars that is a by-pass line
that loop around the pump (<A
href="http://www.perrypumps.com/instructions.htm"
target=_blank>http://www.perrypumps.com/instructions.htm</A>,
Click on Pump and By-Pass Systems). I think the ideas deserve
some checking since it is natural to have this type of regulation to
maintain constant pre! ss! ure in the line before needle
valve. I tried the other day the by-pass to the carburetor but I
installed the T too far from the carburetor and forgot to open the
vent in the tank. Of course the results were bad
since I was developing vacuum in the tank. I wi! ll try these
options of by-pass lines as soon as get warmer. However, I think
someone out there already tried to do this and know results so I am
looking for feed back.</DIV>
<DIV> </DIV>
<DIV>Thanks in advance,</DIV>
<DIV> </DIV>
<DIV>Vicente Bortone</DIV>
<DIV> </DIV></DIV></WMFILTERED></DIV>
<DIV>
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