[NSRCA-discussion] YS140DZ idle question-answer

Tue Aug 1 03:04:14 AKDT 2006

PowerMaster 30%DZ blend. If I were to buy new fuel
right now I would buy 20%, no need for 30%, even at 95
degree F temperatures.

RPM? I don't know, I have not measured it. I will the
next flying session.

The 18.1X10 is heavy, I had to relieve the openings in
the cowl due to the increased rotation of the engine
on the Hyde mount during idle. I'm hoping Mejzlik
comes out with a similar prop.

--- Peter Pennisi <pentagon.systems at bigpond.com>
wrote:

> 
> Bob,
> 
> What RPM are you getting with the 18.1 X 10 APC W
> and what fuel are you
> using?
> 
> -----Original Message-----
> From: nsrca-discussion-bounces at lists.nsrca.org
> [mailto:nsrca-discussion-bounces at lists.nsrca.org] On
> Behalf Of Bob Kane
> Sent: Tuesday, 1 August 2006 1:14 PM
> To: NSRCA Mailing List
> Subject: Re: [NSRCA-discussion] YS140DZ idle
> question-answer
> 
> No. The DZ series does not use a pressurized fuel
> system. The fuel is "sucked" from the tank by the
> fuel
> pump on the down stroke of the intake pushrod (valve
> closing), and "squirted" out to the injector as the
> intake valve pushrod opens the valve. The regulator
> on
> the front of the fuel pump limits the fuel pressure
> by
> opening when the fuel pressure is sufficient to
> overcome the spring tension in the regulator. The
> spring is much stiffer than the spring in the FZ/L
> series motors. There is no low end adjustment on the
> carb in the DZ series, so the regulator is used to
> set
> the idle mixture. Start the engine, set the high end
> needle as you would on any other YS, pull the
> throttle
> back to idle. If the engine slows down and dies, it
> is
> rich, turn the regulator out to lean it. If it
> speeds
> up and dies, it is lean, turn it in to richen it.
> Recheck the high speed needle.
> 
> These engines will not tolerate restrictive fuel
> filters. I am currently using a Sullivan Crap Trap
> to
> keep the big boulders out of the fuel system and it
> is
> working well. I'm still playing with using a check
> valve on the vent side of the tank. It works well
> without it but I get some leakage out of the vent.
> 
> I have recently been through an extensive learning
> experience with the pump system on these engines. If
> the fuel lines past the pump blow off the fittings,
> the pump regulator is set too rich or is sticking
> closed. If you are having trouble with the
> adjustments
> it might be time to have the pump/engine serviced.
> 
> I will say the power of the 160DZ is incredible, way
> more than what is needed to pull my Temptation
> through
> the Masters sequence. I'm running an APC 18.1X10
> prop,
> the thing pulls like a locomotive and slows down as
> if
> you threw the anchor out. Vertical uplines, even
> with
> rolls are just over half throttle. The only possible
> disadvantage is the prop is heavy and will probably
> cause more rapid conrod wear.
> 
> 
> --- vicenterc at comcast.net wrote:
> 
> > Eric,
> > 
> > I got a new YS 160 DZ.  Is this procedure
> equivalent
> > for both engines?   
> > 
> > Thanks,
> > 
> > Vicente "Vince" Bortone
> > 
> > -------------- Original message -------------- 
> > From: "Grow Pattern" <pattern4u at comcast.net> 
> > 
> > Michael,
> >              The big and first thing to remember
> is
> > that the DZ uses a pump. If you keep thinking
> about
> > the pump as a regulator it may not help you set
> your
> > engine. Unfortunately the instructions call it a
> > regulator. The fuel is metered out to the carb by
> > the pushrod action and the "pulsating" crankcase
> > pressure operates the pump side.
> > 
> > The next thing is that the carb does two things.
> It
> > controls the air flow to the inlet valve and the
> > fuel supply to the injector. Even though the
> needle
> > effects all of the fuel flow it is not the right
> > thing to use to get a good idle. Many people
> > accidentally/unintentionally override the pump
> > settings with the main needle to get a good
> low-end
> > rpm.
> > 
> > The "regulator" screw restricts the primary fuel
> > flow and is the one that you must use to set an
> idle
> > and transition. If you get the big brass screw set
> a
> > bit too rich it will keep dousing the plug,
> > especially at low rpm.
> > 
> > The trick to a good setting is to keep closing the
> > pumped fuel supply until the engine will not run
> any
> > more. 
> > 
> > You do this by turning the big brass screw
> clockwise
> > about 1/8 of a turn and then start and warm up 
> the
> > engine. Keep the main needle at about 1.5 turns or
> > more and don't worry if it runs a bit rich as you
> > open the throttle about half way, in short bursts.
> > Do this again and again until the engine will not
> > start or keep running at idle or open up.
> > 
> > You are now very close. Turn the brass screw back
> > anti-clockwise about 1/8 of turn. and see if the
> > engine will start and idle. It should be able to
> go
> > as low as, and hold about, 1.500 rpm.for about a
> > minute. If the throttle smoothly increases the rpm
> > you have a good low-end setting. (Go more "open"
> on
> > the brass screw if it is needed to keep it
> running).
> > 
> > Now is the time set your top-end needle. It may
> need
> > more or less fuel so please open up carefully and
> > listen for the warning "bark". Richen the main
> > needle if it barks. If all goes well, set the
> > high-end needle for max rpm and then richen it
> back
> > about 500 rpm.
> > 
> > After that it should run like a Swiss-watch, start
> > better, and last a good while. It should not quit
> in
> > the air or on the ground.
> > 
> > Please let me know if this worked for you.
> > 
> > Regards,
> > 
> > Eric. 
> > ----- Original Message ----- 
> > From: Michael Cohen 
> > To: NSRCA Mailing List 
> > Sent: Sunday, July 30, 2006 2:31 PM
> > Subject: [NSRCA-discussion] YS140DZ idle question
> > 
> > 
> > OK list, I have a question for you.  I have a
> 140DZ
> > that will not idle below 2300ish RPM.  Richard
> > Lindberg and I have adjusted the regulator, but it
> > appears to have little or no effect.  I might be
> > able to get one flight in, but eventually, on a
> down
> > line, it will die and 7 dead sticks are not that
> fun
> > to try.   Full power seems to hold just fine.  We
> > figured there might be an air leak, and that is
> why
> > it seemed to idle worse after a warm up flight, so
> I
> > replaced the valve cover gasket and the other
> > gaskets at the backplate, but that did not seam to
> > make a difference.  Anybody got any ideas besides
> > the usual OS/Webra/Mintor/E-power/power slope
> > soaring comments?
> > 
> > 
> > 
> > _______________________________________________
> > NSRCA-discussion mailing list
> > NSRCA-discussion at lists.nsrca.org
> >
>
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion>
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> > NSRCA-discussion at lists.nsrca.org
> 
=== message truncated ===

Bob Kane
getterflash at yahoo.com

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