YS 1.40 Sport

[Troy Newman]

Jon,

If you remove the throttle barrel you will see the air bleed screw really only controls the size of the air hole in the intake tube side of the throttle barrel. What Buddy is talking about is...remove the air bleed screw all the way...And drill this hole slightly bigger clean it all up and de-bur the holes...then re-install the air bleed screw....The result is you now have more adjustment. Its really pretty simple procedure...But actually pretty rare that its needed. Another possible solution is that you reg is a little too rich. This really controls mid-range stuff. I would lean the reg a little say 1/4-1/2 turn, then re-set everything else....On the pressure regulator IN is Lean....Don't be confused with the DZ...the DZ doesn't have a reg its an actual fuel pump...And IN is rich on the DZ's. This leaner reg will probably solve you mid range problem if it doesn't then drilling the hole should help...

 Perhaps your fuel, and prop combo are resulting in the need like the Buddy and crew. When you remove the barrel you will see the hole with the end of the screw in it. If any of the hole is blocked off by the screw then your hole can be bigger by adjusting the screw further out.....But when the screw reaches about 3 turns open the hole is max size...If its still rich then I suggest drilling it...

Always remove the throttle barrel out the side with the air bleed, and then insert back tracking the same way. There is a throttle barrel seal...DO NOT run that seal across the hole for the throttle barrel stop screw. Sometimes this hole has a bur on it on the inside where it was tapped for the thread. This bur will or can cut or knick the seal and it will leak. So just remember the seal is on the air bleed side of the barrel(opp the throttle arm)....So remove the arm and push out...then insert the arm side first...Some light oil help get it back in place without damage to the seal.

This air bleed used to be a problem back when the 120NC and SC first hit the market. The size of the hole was too small and there was not a screw in the hole to make adjustments. I was running the motors up at 6000ft in Denver and we found in our thin air the air bleed holes had to be bigger...

A little bigger like 2 drill sizes works if drill is needed.

Troy Newman
  ----- Original Message ----- 
  From: JonAlan Wise 
  To: discussion at nsrca.org 
  Sent: Friday, August 20, 2004 10:22 PM
  Subject: Re: YS 1.40 Sport


  Buddy, Can you explain this fix? I have a new 140 sport that has this problem. I called YS Performance and talked to them about it they told me this was the fix. I told them I would send it in but maybe I could do it myself. Could you explain? Thanks Jon Wise 
  BUDDYonRC at aol.com wrote: 

     BobThe 140-Sport is stronger than the old 140-FZ, It has the 140-L Carb, Piston and the new rotary valve now used on the 140-DZ they have gone back to pressure through the crank shaft to the diaphragm which also improves lubrication to the cam area similar to the old air chambers the only problem we have seen, and there are five of them being used locally is that the hole in the throttle barrel on the low end side needs to be drilled out to 1/8" diameter to eliminate the mid range from loading up. we are running Magnum 1-1/2 fuel, 16x11APC and turning 8400 to 8800 two of these are on Temptations and two on my original designed Eagle One Larry Mercer was third in Advanced at the Nat's with his.Buddy Brammer
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