[NSRCA-discussion] YS140DZ idle question-answer

Tue Aug 1 05:36:03 AKDT 2006

">> I got a new YS 160 DZ.  Is this procedure equivalent
>> for both engines?"   
It's the same for the 1.40DZ and the 1.60DZ.

Eric.

----- Original Message ----- 
From: "Bob Kane" <getterflash at yahoo.com>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Monday, July 31, 2006 11:14 PM
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?
>> 
>> 
>> 
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> 
> Bob Kane
> getterflash at yahoo.com
> 
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