YS 160 DZ

[Ed Miller]

I love the YS engine design, no doubt it produces the "flavor" of power most easily managed by most in a pattern ship. It is a miniature mechanical marvel, to think it's footprint hasn't changed since it's introduction as a lowly 120 small bearing, small exhaust valve, over compressed SF. However, that is part of the problem, the design was probably at it's peak in 140 FZ and/or L form. It could withstand somewhat minor QC issues and believe me, if you've ever measured YS parts in bulk, there are QC issues. I still have 2 YS 120AC's, dinosaurs to some but good running engines for 10 pound planes that thrive at quiet rpms ( 7600 to 8000 ). However I have switched to the dark side, OS 2 cycles as they are lighter, easier to maintain ( less parts ), with out a doubt more powerful and OS'es QC is first class. The current crop of YS 4 cycles shake very hard, consume too much fuel, have to be run at a nosy rpm range and quite frankly are unreliable for the average pattern flier, although unreliable can be said about OS, Mintor and Webra too, depends on who you talk to. Unreliable in the 2 stroke seems to be the learning curve of pipe length to prop load issues. To be honest, the only 100% trouble free YS engines I have ever owned were ones I blueprinted, modified and lovingly hand assembled for myself and those I built engines for in the Northeast including a past Nats Master's champion. 
Ed M.
  ----- Original Message ----- 
  From: mike mueller 
  To: discussion at nsrca.org 
  Sent: Tuesday, September 28, 2004 7:51 AM
  Subject: Re: YS 160 DZ


   Troy I've made a few observations about the YS engines after using them for 3 out of the last 4 years. We have what I believe to be the largest pattern club in the country here in Chicago with at least 15 dedicated flyers at our home field almost all use YS product.. 
   I think the YS DZ is the most powerful engine available today I also think they are very unreliable. We've had over a 60% failure rate this year alone with the DZ's being used here. When they run they are awesome and that's what keeps most of us here willing to fight thru the problems. We have had a lot of problems with the pumps. One of our sponsored flyers went thru 3 pumps on 1 engine this summer. These are people who have strong relationships with Verano. 
   I have had a very good engine this year but it has continued to break head gaskets all year long and it leaks fuel to the point of being nicknamed the "Exxon Valdez". She's going back to the factory this week.
   I hope that YS takes there time with the release of the 160DZ and makes them more reliable. One of our really top flyers here has had so many problems with his 2 DZ's this year that it all but ruined his season. The guys a top auto mechanic and he knows engines.
   I'm going to stick with the DZ because I think it's like F1 racing. On the edge! Still one should know what there getting into with these expensive, finicky and complicated buggers.
   Also I know that our group has enough mechanical smarts to setup and run engines correctly. I'm hoping for the best here. Thanks, Mike

  Troy Newman <troy_newman at msn.com> wrote:
    Mike,

    I have not seen the MA ad yet, but I do know that Yamada was playing with some new pump designs. This was a two fold deal: #1 make the pump easier to produce (less $$ and less hassles) and #2 to make the pump a more user friendly easier to adjust version. Now with this re-design I believe they found out some things in the longevity side of the equation and these applied to the std 140DZ pump. Then the 140DZ pump got an upgrade and met the goals of the new pump design and kept the parts the same in terms of looks. My original 160 DZ has the same pump as the 140DZ. 

    I have run both pumps and they run the same. Then again I don't tend to have problems with my motors. They just run and run and run. I actually wear them out after hundreds of flights. 

    TN
      ----- Original Message ----- 
      From: Zoro1024 at aol.com 
      To: discussion at nsrca.org 
      Sent: Monday, September 27, 2004 8:19 PM
      Subject: Re: YS 160 DZ


      Kind of wonder myself, I see their add in the AMA magazine shows a different pump arrangement.  Something has got to make them better, I've become the postman's best friend mailing the 140's back to NV.



      Mike


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