<div>There is no such thing as gravity, the earth sucks!</div> <div> </div> <div>There must be vacuum!<BR><BR><B><I>twtaylor <twtaylor@ftc-i.net></I></B> wrote:</div> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">There is no such thing as vacuum on this earth. It's differential pressure.<BR>:)<BR><BR>-----Original Message-----<BR>From: nsrca-discussion-bounces@lists.nsrca.org<BR>[mailto:nsrca-discussion-bounces@lists.nsrca.org] On Behalf Of Grow Pattern<BR>Sent: Tuesday, August 01, 2006 9:52 AM<BR>To: NSRCA Mailing List<BR>Subject: Re: [NSRCA-discussion] YS140DZ idle question-answer<BR><BR>It has to be in the plane :-)<BR><BR><BR>The pumping action allows the tank to be on the CG just like the pressure <BR>systems.<BR><BR><BR>Regards,<BR><BR>Eric.<BR>----- Original Message ----- <BR>From: "John Ferrell" <JOHNFERRELL@EARTHLINK.NET><BR>To: "NSRCA Mailing List" <NSRCA-DISCUSSION@LISTS.NSRCA.ORG><BR>Sent:
Tuesday, August 01, 2006 9:49 AM<BR>Subject: Re: [NSRCA-discussion] YS140DZ idle question-answer<BR><BR><BR>> How critical is tank location?<BR>><BR>> John Ferrell W8CCW<BR>> "My Competition is not my enemy"<BR>> http://DixieNC.US<BR>><BR>> ----- Original Message ----- <BR>> From: "Earl Haury" <EHAURY@HOUSTON.RR.COM><BR>> To: "NSRCA Mailing List" <NSRCA-DISCUSSION@LISTS.NSRCA.ORG><BR>> Sent: Tuesday, August 01, 2006 7:50 AM<BR>> Subject: Re: [NSRCA-discussion] YS140DZ idle question-answer<BR>><BR>><BR>>> Bob gets the award for proper description of the YS D engine series fuel<BR>>> system. Yamada san is a very innovative designer!<BR>>><BR>>> As Bob states - fuel is "sucked" from the tank on the pump piston<BR>>> downstroke<BR>>> (low pressure in the pump results in atmospheric air pressure "pushing"<BR>>> fuel<BR>>> from the tank). Appropriate inlet / outlet check valves within the
pump<BR>>> provide for incoming fuel draw or outgoing fuel injection.<BR>>><BR>>> The pump is a positive displacement piston pump, ingeniously fitted into<BR>>> the<BR>>> intake valve pushrod which provides motion that is timed to the intake<BR>>> stroke of the engine. The output of the pump is determined by pump size /<BR>>> stroke and pump rate (engine rpm) - this output is controlled by the<BR>>> needle<BR>>> valve (high end) and the throttle barrel slot. As with all positive<BR>>> displacement pumps transferring fluids (non-compressible), there must be<BR>>> some way to accommodate excess volume (i.e. closing the throttle at high<BR>>> rpm) or parts will break! A spring vs. fuel pressure against a diaphragm<BR>>> regulator provides an internal return path from the pump outlet to the<BR>>> pump<BR>>> inlet - recirculating excess fuel. Another ingenious YS design <BR>>>
application<BR>>> is that the regulator spring pressure is modulated by crankcase pressure<BR>>> (against the spring side of the diaphragm) - increasing pressure at high<BR>>> rpm. Because of this - idle mixture can be changed by adjusting the idle<BR>>> fuel pressure with the tension of the regulator spring. Of course -<BR>>> changing<BR>>> the spring tension also affects the high end pressure (CC + spring) and<BR>>> must<BR>>> be accommodated with appropriate needle valve changes.<BR>>><BR>>> For those still convinced that the regulator on the front of the pump is<BR>>> actually "the pump" - I suggest that you remove the crankcase pressure<BR>>> line<BR>>> between the regulator and the engine and run the engine (it'll lean out <BR>>> at<BR>>> WOT but can be richened with the needle) - fuel will still be pumped just<BR>>> fine!<BR>>><BR>>>
Earl<BR>>><BR>>><BR>>><BR>>><BR>>> ----- Original Message ----- <BR>>> From: "Bob Kane" <GETTERFLASH@YAHOO.COM><BR>>> To: "NSRCA Mailing List" <NSRCA-DISCUSSION@LISTS.NSRCA.ORG><BR>>> Sent: Monday, July 31, 2006 10:14 PM<BR>>> Subject: Re: [NSRCA-discussion] YS140DZ idle question-answer<BR>>><BR>>><BR>>>> No. The DZ series does not use a pressurized fuel<BR>>>> system. The fuel is "sucked" from the tank by the fuel<BR>>>> pump on the down stroke of the intake pushrod (valve<BR>>>> closing), and "squirted" out to the injector as the<BR>>>> intake valve pushrod opens the valve. The regulator on<BR>>>> the front of the fuel pump limits the fuel pressure by<BR>>>> opening when the fuel pressure is sufficient to<BR>>>> overcome the spring tension in the regulator. The<BR>>>> spring is much stiffer than the spring in the
FZ/L<BR>>>> series motors. There is no low end adjustment on the<BR>>>> carb in the DZ series, so the regulator is used to set<BR>>>> the idle mixture. Start the engine, set the high end<BR>>>> needle as you would on any other YS, pull the throttle<BR>>>> back to idle. If the engine slows down and dies, it is<BR>>>> rich, turn the regulator out to lean it. If it speeds<BR>>>> up and dies, it is lean, turn it in to richen it.<BR>>>> Recheck the high speed needle.<BR>>>><BR>>>> These engines will not tolerate restrictive fuel<BR>>>> filters. I am currently using a Sullivan Crap Trap to<BR>>>> keep the big boulders out of the fuel system and it is<BR>>>> working well. I'm still playing with using a check<BR>>>> valve on the vent side of the tank. It works well<BR>>>> without it but I get some leakage out of the
vent.<BR>>>><BR>>>> I have recently been through an extensive learning<BR>>>> experience with the pump system on these engines. If<BR>>>> the fuel lines past the pump blow off the fittings,<BR>>>> the pump regulator is set too rich or is sticking<BR>>>> closed. If you are having trouble with the adjustments<BR>>>> it might be time to have the pump/engine serviced.<BR>>>><BR>>>> I will say the power of the 160DZ is incredible, way<BR>>>> more than what is needed to pull my Temptation through<BR>>>> the Masters sequence. I'm running an APC 18.1X10 prop,<BR>>>> the thing pulls like a locomotive and slows down as if<BR>>>> you threw the anchor out. Vertical uplines, even with<BR>>>> rolls are just over half throttle. The only possible<BR>>>> disadvantage is the prop is heavy and will probably<BR>>>> cause more rapid conrod
wear.<BR>>>><BR>>>><BR>>>> --- vicenterc@comcast.net wrote:<BR>>>><BR>>>>> Eric,<BR>>>>><BR>>>>> I got a new YS 160 DZ. Is this procedure equivalent<BR>>>>> for both engines?<BR>>>>><BR>>>>> Thanks,<BR>>>>><BR>>>>> Vicente "Vince" Bortone<BR>>>>><BR>>>>> -------------- Original message -------------- <BR>>>>> From: "Grow Pattern" <PATTERN4U@COMCAST.NET><BR>>>>><BR>>>>> Michael,<BR>>>>> The big and first thing to remember is<BR>>>>> that the DZ uses a pump. If you keep thinking about<BR>>>>> the pump as a regulator it may not help you set your<BR>>>>> engine. Unfortunately the instructions call it a<BR>>>>> regulator. The fuel is metered out to the carb by<BR>>>>> the pushrod action and the "pulsating"
crankcase<BR>>>>> pressure operates the pump side.<BR>>>>><BR>>>>> The next thing is that the carb does two things. It<BR>>>>> controls the air flow to the inlet valve and the<BR>>>>> fuel supply to the injector. Even though the needle<BR>>>>> effects all of the fuel flow it is not the right<BR>>>>> thing to use to get a good idle. Many people<BR>>>>> accidentally/unintentionally override the pump<BR>>>>> settings with the main needle to get a good low-end<BR>>>>> rpm.<BR>>>>><BR>>>>> The "regulator" screw restricts the primary fuel<BR>>>>> flow and is the one that you must use to set an idle<BR>>>>> and transition. If you get the big brass screw set a<BR>>>>> bit too rich it will keep dousing the plug,<BR>>>>> especially at low rpm.<BR>>>>><BR>>>>> The trick
to a good setting is to keep closing the<BR>>>>> pumped fuel supply until the engine will not run any<BR>>>>> more.<BR>>>>><BR>>>>> You do this by turning the big brass screw clockwise<BR>>>>> about 1/8 of a turn and then start and warm up the<BR>>>>> engine. Keep the main needle at about 1.5 turns or<BR>>>>> more and don't worry if it runs a bit rich as you<BR>>>>> open the throttle about half way, in short bursts.<BR>>>>> Do this again and again until the engine will not<BR>>>>> start or keep running at idle or open up.<BR>>>>><BR>>>>> You are now very close. Turn the brass screw back<BR>>>>> anti-clockwise about 1/8 of turn. and see if the<BR>>>>> engine will start and idle. It should be able to go<BR>>>>> as low as, and hold about, 1.500 rpm.for about a<BR>>>>> minute. If the
throttle smoothly increases the rpm<BR>>>>> you have a good low-end setting. (Go more "open" on<BR>>>>> the brass screw if it is needed to keep it running).<BR>>>>><BR>>>>> Now is the time set your top-end needle. It may need<BR>>>>> more or less fuel so please open up carefully and<BR>>>>> listen for the warning "bark". Richen the main<BR>>>>> needle if it barks. If all goes well, set the<BR>>>>> high-end needle for max rpm and then richen it back<BR>>>>> about 500 rpm.<BR>>>>><BR>>>>> After that it should run like a Swiss-watch, start<BR>>>>> better, and last a good while. It should not quit in<BR>>>>> the air or on the ground.<BR>>>>><BR>>>>> Please let me know if this worked for you.<BR>>>>><BR>>>>> Regards,<BR>>>>><BR>>>>>
Eric.<BR>>>>> ----- Original Message ----- <BR>>>>> From: Michael Cohen<BR>>>>> To: NSRCA Mailing List<BR>>>>> Sent: Sunday, July 30, 2006 2:31 PM<BR>>>>> Subject: [NSRCA-discussion] YS140DZ idle question<BR>>>>><BR>>>>><BR>>>>> OK list, I have a question for you. I have a 140DZ<BR>>>>> that will not idle below 2300ish RPM. Richard<BR>>>>> Lindberg and I have adjusted the regulator, but it<BR>>>>> appears to have little or no effect. I might be<BR>>>>> able to get one flight in, but eventually, on a down<BR>>>>> line, it will die and 7 dead sticks are not that fun<BR>>>>> to try. Full power seems to hold just fine. We<BR>>>>> figured there might be an air leak, and that is why<BR>>>>> it seemed to idle worse after a warm up flight, so I<BR>>>>> replaced the valve cover
gasket and the other<BR>>>>> gaskets at the backplate, but that did not seam to<BR>>>>> make a difference. Anybody got any ideas besides<BR>>>>> the usual OS/Webra/Mintor/E-power/power slope<BR>>>>> soaring comments?<BR>>>>><BR>>>>><BR>>>>><BR>>>>> _______________________________________________<BR>>>>> NSRCA-discussion mailing list<BR>>>>> NSRCA-discussion@lists.nsrca.org<BR>>>>><BR>>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion><BR>>>> _______________________________________________<BR>>>>> NSRCA-discussion mailing list<BR>>>>> NSRCA-discussion@lists.nsrca.org<BR>>>>><BR>>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>>>><BR>>>><BR>>>> Bob Kane<BR>>>> getterflash@yahoo.com<BR>>>><BR>>>>
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