30 second setup for the YS 140DZ

[Troy Newman]

Don,

Yes the "V" on the barrel is the production version. There were only a few of the non-V barrels out there on the motors that a few of us had before the actual release. The initial thing on the original prototype is they were tough to lean out on the bottom end and get a solid idle like previous motors...It would be a little rich and never die in the air....but on the ground sometimes it would just load up a little after a fairly long 90sec+ idle.....To my knowledge all of the production motors have had this notch to lean the bottom end slightly....Another thing to my knowledge there have not been the changes the in throttle barrels like on previous versions of YS motors....I know many people felt it was the throttle barrel of the day....as many were quite different. I have a new DZ from the latest shipment and I have a production Carb on my original test motor (may of 2000)....This carb was changed out when the production motors were released. That first run production barrel and the new latest run barrel are the same...I have looked closely at the scroll and can't find any difference.... 

My current setup is running about 1-3/8 to 1.25 open on the top end and just inside flush maybe about 3/4 turn to a turn.....The idle is very good and the transition is great...If you get too lean of idle what will happen is the motor will rev right off idle as you throttle up then richen up and transition fine....I use this rev up as a key its too lean and richen past this point slightly....

Keep up the practice! Its going to be a fun event!

When are you going down?....I'm going to be at my wife's parents on about June 1-2 and they live about 90mins north of the Woodruff contest site. My guess is we will go down and fly on Tuesday and then do the airplane checkin on Weds morning.


Troy
  ----- Original Message ----- 
  From: don szczur 
  To: discussion at nsrca.org 
  Sent: Wednesday, May 14, 2003 9:16 PM
  Subject: Re: 30 second setup for the YS 140DZ


  Actually, like most things, they develop and refine over time.  I noticed when I changed my YS out (it ran great but after about 24 gallons, its way past when it should normally be serviced) with my backup DZ, I noticed that the backup had a throttle barrell with a small notch, or "v" cut in the front edge of the butterfly.  It acts like an air bleed when the throttle is shut.  Any case, this version of the (carb) runs significantly leaner on the low end. A characteristic of lean low end is a hesitation when advancing the throttle from idle to full.  I screwed the pump in about a half turn IN past flush, from the housing point to bump up the pressure and thus richen the idle so it does not hesitate much.  No difference in the air from the other DZ.  So, the type of carb design may impact the pump position.  The same process used below to adjust though.
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