The YS engines need 30% nitro fuel to run properly, so, it results in a very expensive engine, if you use a lower nitro content fuel, you will have idle and transition problems besides of lack of power. Regarding YS service and technical support, in my personal experience, it is very deficient. I have had very bad experience with the YS technical support (YS performance). I lost my money by purchasing a YS engine that never ran properly from the beginning, YS Performance did not repaired my engine, they do not honor the warranty compromise. I do not recommend YS engines, I think that OS is by far a better option.

YS Performance is the importer of engines into the USA, more correctly into North America. YS Performance is not the Warranty service center for YS Japan.

I have spoken to many folks from Eruope that and other parts of the world that have used YS Performance for Service work but in these cases the engine work is not warranty unless it was purchased through a North American hobby shop like Central Hobbies or Horizon Hobby.

Basically it boils down to the warranty work performed in on their North American engines and not all YS engines. This is unfortunate for folks living in other parts of the world but is a simple fact of life. If I buy a $100 tail wheel from Japan and then expect it to be replaced under warranty when it breaks...I need to go to Japan and get it worked out. Reality is its tough.

Conversly If you purchase an OS engine and expect Hobbico to service it when you didn't buy it from Tower Hobbies and you live outside North America you will get the same answer. I would say that YS and OS engines are both very high quality engines.

The YS doesn't have to run on 30% nitro Cool Power also makes a 20% Performance Heli fuel that is less nitro than the 30% heli and it runs extremely well on this also. Most choose 30% for the power and performance...but its not required.

Sorry for your frustration with it. If you want it fixed and running properly before its returned to you YS Performance will do that and they are extremly good at it.....They are not Yamada of Japan...they are under an agreement to service the engines they import.

Troy Newman
Team YS Performance

I think most running problems with the YS 4-strokes are owners not being experienced
enough with the engine to adjust it properly. I had all kind of problems getting mine to
run right and almost lost my pattern airplane because of a deadstick low and downwind
at a contest last year. I was sure cursing that engine until Earl Haury helped me adjust
it properly and it's run perfectly ever since. I haven't even touched the needle valve in
over a year and I don't think any 2-stroke is even close in torque and power. If you are
having problems with the YS ask for help from someone who is not having the same problems.

tommy s

You summed it up Tommy.

I can tell you that the DZ specifically has a very tight set of conditions it wants in order to perform. The first few runs and tuning are CRITICAL. if you aren't experienced enough yourself, seek the help of someone who is. Luckily when I got my first one, I had Jim Ivey to teach me how to set it up. Jim is one of the best in the southeast with the YS engines. His ear for it is uncanny. He can hear subtleties that I can't. I'm learning fast just by being around him. I can set one up very well myself and diagnose most problems fast. But Jim has some kind of zen going on with the YS.

The other key to this engine is that they do require attention. They will let you know in no uncertain terms when they're not happy. The last thing you want to do is try to fix it with the needle. If you're a needle tweaker, you'll blow this thing up. Once it's set, DON'T TOUCH IT!!!!! If possible make it where you can't even get to the needle easily just to remove the temptation. Because every time you start it on the ground, it's a little different first run of the day. You can swear something is wrong when it's NOT. Just fly it. Then if it starts hammering in the ear, ONLY then should you check to see if adjustments are needed.

The other thing I strongly reccomend is a header tank. I use a 2 ounce header tank with the fuel pickup for the engine dead center of the tank. Stiff tube, end of it right dead in the middle. Location of the tank itself doesn't really matter, but the closer to the engine the better. The line to the tank is set up like a vent line in a normal tank, in and to the top. Put a good fuel filter in line before the engine and after the break in the line. The header tank removes all inconsistencies with the way this engine runs. Everyone having a problem I have seen around here is not running this tank for whatever reason. It wants this tank, because it's very intolerant of air bubbles. You have to balance your plane with this tank full, and it gives you NO warning that it's low on fuel before it dies hard and throws the prop. So set a timer and be certain, don't press it.

One other piece of advice if you are used to 2 strokes.......do NOT run this engine to full power cold. Start it, give it a few clicks, and let it warm up, slowly advancing the throttle to about 1/3. After about 20 seconds, you can slowly advance to full power. if you start it and immediately go to full power, say goodbye to your prop, spinner, and maybe half of your face. (Ask Lamar Blair).

As Troy mentioned it doesn't require 30%, but let me tell you, if you ever run Cool Power 30% heli in this engine you'll never run anything else. That actually applies to any 4 stroke in my opinion, all of the guys at my club started using it in thier Saitos and OSs, and the power and consistency of thier engines were noticably different. I'm sure other fuels are fine, Cool Power is just the easiest to get around these parts. I have run it exclusively since the early 80s. The fact that I am now part of Team Cool Power was about 20 years after the fact....LOL

The OS 160 is a powerhouse as well, but it's not the same as a DZ 160. It's apples and oranges, you can't really compare them because they are so different. They make very close to the same top end power, and idle about the same....on the ground....the OS is hard to spool down fast on a downline so if you have a clean fast plane, you have to lead the throttle. I ran the OS 140 for years (and swore by it, still do for many applications) and the hardest thing for me to get used to was the instant throttle response of the YS. It will kick your rear if you lead it too much. You either have to use a broad curve or be very comfortable with the left stick.

Until the DZ 160 came out, I could really see no advantages personally to using a YS in the big picture. Dead sticks were an every day occurence around here, and they didn't make any more power than the OS, so to me it was more of a liability than an asset. Then I watched Jim Ivey run a DZ 160 for 2 seasons straight....it always cranked, always ran, made awesome power, and I never saw him touch it...ever. Went to the nats last year, and for the first time ever, felt like I just didn't have enough power. I stayed at Arch Stafford's place for a few days before the Nats, and he told me "Watch...you're going to get there, the heat and humidity will be ridiculous, and watch...you'll run out of power." I laughed it off. Then he spent the next 3 days saying "I told you so" and laughing at me. I made the switch and haven't looked back. If they keep making engines like this, I never will.

Now if my 170 would ever show up.......LOL

-Mike

Dear Troy Newman,

Thanks for your answer. Firstly, sorry for my English, it is not my native language. I purchased the defective YS engine from Central Hobbies (USA), invoice No. 91799, so, I got the YS P. warranty, is not it ?. I purchased this engine because of the YS “good reputation� and also because the YS operator’s manual said that the engine can run on 15 % nitro. That is not true, the YS engine I bought from Central Hobbies (USA) does not run on 15 % nitro, it only runs on 30 % nitro[/color]. I also tried 20% nitro fuel (more expensive) but the engine did not like it, I got bad idle and bad mid range transition. Trying to fly my model with this YS engine on 15% nitro I had several dead stick landings before I had a fatal accident, I lost my plane. The 30 % nitro fuel is extremely costly in my country, so, I wanted an engine that can run on 15 % nitro. I read the YS operator’s manual before purchasing the engine, I trusted to YS, I got the engine, now I feel deceived !. Well, I sent the engine back to repair to YS P., I had to pay the shipping charges to the USA and then back again to Caracas, it was costly. I received the “repaired� engine back from YS P. as bad as I sent it, the defective YS engine did not run on 15 % nitro, again. Then, I contacted YS P. by e-mail, I was answered by Dave that: “…..The only thing required on your engine was a piston modification… “ (some small holes were opened in the piston to ensure proper fit of the ring to the sleeve). Can you imagine it ?, a brand new engine needs to be modified by the seller in order to intend it to run ?. That is crazy !!. I paid to YS for an engine and, after sale, they are “experimenting� on it!!. Is that a honest business ? . No, it is a fraud !!. One more time, that is crazy!. YS took my money and gave me a problem instead a satisfaction!. On top of that, I never received an answer from “Mr.� Verano to my e-mails when claiming because of the defective engine and the bad service. I sent several e-mails to him but it seemed to “Mr.� Verano that Caracas is too far from Gardnerville to give proper after sale service to such a “distant� client ! He did not honor the warranty for my engine. “Mr.� Verano never assumed his responsibility for my defective engine and his bad service. I think that, In spite of I am not an USA customer, my money is as valuable as the money of an USA customer. If I were a USA client (citizen), most probably I would not had suffered such a discrimination !
I do not want to be ironic but I have to say that, to be honest, Yamada Mfg. should rewrite their operator’s manual as: some YS engines might run on 15-20 % nitro, most of them only run on 30 %.This four stroke YS engine has been the most expensive and frustrating engine I have had in my life !. I am flying models since 1973, that is 34 years. I was a YS engines user for a long time, had various of the two stroke engines. I purchased my first YS (along with a JR radio) from Circus Hobbies, do you remember them ?.
I have never had such a problem with a OS engine. I have to repeat that I do not recommend YS engines anymore because, in my personal opinion, they are not reliable and mainly because the after sell support is extremely bad. To me, the OS 160 is by far a better option than any YS engine. Actually, I am about to start running a brand new MINTOR 170 engine on an Impact plane. Still waiting for the announced OS 200, but YS, never, never again in my life!

Regards
Enrique Grujicic R.

Enrique,

Its unfortunate that you you feel you the way you do.



I think you will be very happy running the OS engine. They make a very fine product.



Troy Newman
Team YS Performance

For the record, Ys engines do run quite happily ion 20%. Infact, if I am not mistaken, japanese flyers can't use 30% nitro so the engines are designed with 20 something percent nitro in mind. I am not completely sure about this, maybe a japanese flyer could clear it up. Also, I ran a 140 for many years on 15% coolpower, it ran a treat. However, it was set up by a very competant YS guru.

In Japan, maximum nitro allowed is 20% or 22.5% and no more so YS engines are perfectly happy with this. I personally have run every YS engine from the 61 2 strokes to all the 120 variants and all the 140s except the DZ with coolpwer 15% with no problems whatsoever despite very high humidity where I live. I have only run the 140DZ and 160DZ on 20% and 30% nitro but see no reason why 15% nitro wont work. Properly tuning the engine is the key. Tried using 10% nitro on the YS and coulnt get it to run like I wanted so I would say that either I am not a good enough engine tuner to make YS engines run at 10% nitro or YS engines wont run right at less than 15% nitro.

Enrique,

I'm very sorry to hear about your troubles with the YS. It is definitely finicky and picky, and wants a certain set of conditions in which to run. It is very purpose-built. Which model of YS was it if I may ask? What brand of fuel? I will tell you that the YS DZ160 is a very solid great running engine, and normally trouble free, but it demands exacting set up and conditions or it is simply unhappy. Flexible, it is not. Do not read this as saying you are/were doing anything wrong. The drilling of the holes in the piston makes me think it may have been an older 140L perhaps? Just guessing.

As to your comments above, this is my opinion only: ditch the Mintor and go with the OS 160. In my experience the Mintor is even more finicky than the YS. Beautiful, well made engines, and they are getting better, but the break in on these engines is crucial and extremely difficult. They overheat easily and the fuel metering system is somewhat suspect. That said, if you can get it properly broken in, they make good power. But you may be much more pleased with the OS 160. And this is just my opinion from what I have read so far.

If you do a search on some of my older posts, you will see how anti-YS I was in the past. I simply could not see any advantage to these engines, and they were more of a liability than an asset for me. Last year I had to make a choice between the YS 160 and the OS 160. I had been running the OS 140RX for years exclusively, but I felt I was finally reaching a point in my flying where I needed more power. My decision to go with YS was based on first hand experience with a couple that had run very strong and consistently for 2 years straight. As in, no service whatsoever except a glow plug occasionally. This was dead opposite of what I had seen from the older versions, which were a crap shoot in this part of the world, from what I was seeing. I did not see the same behavior from the DZ160 so I decided to try one. I was instructed very closely and thoroughly by Jim Ivey, one of the best YS gurus in the southeast. I learned fast that this engine is fanastic, but initial set up is crucial. Once it's set, forget it. Mine is in the same place it was last August and has many cases of fuel through it, and I love it!!! For me it is a great solution, but I would be fast to say it is NOT for everyone. It is the best engine out there right now for doing what I want an engine to do.

What level/class of pattern do you fly? If you are not flying FAI, I certainly would say it is more important to get a reliable engine that works for YOU. In the states we have lots and lots of YS "experts", so it is easy to recommend this beast to almost anyone....almost. For anyone on thier own, I would advise them so seek out someone to help them get this engine set up properly and teach them the subtle habits of this engine. Once set, you do not touch it. Anyone who feels the need to tweak a needle before every flight can expect this engine to blow up in thier face...because it sounds different on the ground on the first run almost every time. You have to trust that it is set up right and fly it. it can try and trick you into fooling with it.

In your specific case, I'd strongly recommend the OS 160, for what it's worth. if you don't quite need that much power, the 140RX is about as simple as it gets, and is probably the easiest engine to set up and run of them all. All of the engines we use have specific things you have to do to them that are beyond what the manual says, and you have to search out the info sometimes. Jon Lowe's "OS 160 cookbook" article for the K Factor we did last year was the best I have ever seen. The DZ 160-170 needs an article like this, but it might take 5 parts to cover everything as thoroughly as Jon did with the OS

Since I was the editor at the time, I have his article and his updates in PDF form. if you want/need a copy, email me at [email protected] and I will gladly send you the file if it's ok with Jon. in fact, if jon doesn't care, I will organize it and put it on my site for download. I want to do one for the DZ as well over the next few months, I think it would benefit people greatly.

Good luck,
-Mike

Dear Mike,

Thanks for your comments. Regarding the problem I had with the YS engine I prefer not to go deeper on this. I feel I should not continue thinking on this bad experience, it is enough for me. I will leave it on the past. Thanks for your understanding.
Most important for me at this time are your comments on the Mintor engine. Thanks for your opinion on the Mintor but I can not discard this engine, I have already purchased it along with the two headers (medium rise and high rise) and Mintor carbon pipe. It is NIB but not easy to sell here. I do believe the OS 160 could be more easy to deal with but now I have to try to do the best I can do with the Mintor. I appreciate your advice on the proper break-in of this engine, after I get it running I will inform how is it performing.
It is nice that you have success with your YS. That is the idea, I mean, you got a satisfaction for the money you paid, that is great !
Actually I am practicing the FAI F3A P-07, not complete, I need much more practice in order to perform it well. I am finishing a 2+2 pattern plane (Impact). I guess I can improve a lot with this model. There are not many P-07 competitors in our country. At our group, a friend of mine is running a OS 140RX (simple running and good power), he seems to be happy with this engine although he had bearings problems recently, guess no more than one hundred flights, he already got new original bearings. Another friend is running OS 160, it is performing very well with Perry pump and pipe, easy running too. At this time there are not YS 160’s running at our field (Caracas) but another friend (Alejandro) is about start running a brand new DZ 160, I wish good look to him with this engine ! (I will be observing it closely).

Thanks for your interest

Regards

Just trying to help [8D]

Regarding the mintor 170, I strongly suggest you contact Lance at www.aeroslave.com before you crank this engine the first time. Cooling this beast until it is properly broken in is the key. Lance has played with them for years now, and he probably knows this engine as well as anyone. Just realize that it has it's quirks, and know them well before ever making the first run. They have gotten better over the years and are a good engine. But they run very similar to the Webra in many respects, just more top end usually.

I urge you to talk with him soon. Just to make sure and take no chances, because it seems customer support in your part of the world is a factor.

Good luck and good flying!
-Mike

Mike, Thanks again.