Fear of YS engines
 

I have been in the RC airplane/helicopter hobby for more than 20 years. about 20 years ago after reading a Clarence Lee article about the YS 120SC I went out and bought 2. I was totally pumped and
started talking to other fliers and heard nothing but horror stories so they sat in my shop for 5 years untouched. Then one day I met this guy and he kept saying " why are you still flying 2 strokes and I said the four strokes are too much trouble. We flew together the whole summer, and he was flying Saitos and was terrible at tuning an engine so I always tuned them both new and old. Over the winter I purchased a Funtana 90 and put one of the YS 120 sc motors on it. The motor started right up and it took me several minutes to get it running right and the first flight was a mess because I set the engine too rich and it ran out of fuel in just a few minutes and I had a hard landing in a corn field. I leaned the engine and tried again and wow the power the throttle response... I was in love. One more tweek to the engine and I did not touch it for 2 yrs when I changed fuel. I now own 12 YS engines and except for my gassers, YS is all I fly. Have I had any problems? Yes, but mostly hoses or dumb self inflicted things. I truely think that if someone takes a YS motor and follow the instructions they tune as easily as any other. My only regret is that YS doesn't have anything in the 50cc arena and I can go all YS. I have two YS engines that I purchased because guys said they could not get the to perform, I run them and they have never been to YS or any place for any repair. What sparked this outburst you ask? I just got my DZ175cdi and I can't wait to run it.


So don't fear the YS, embrace one and feel the power.


Just my two cents
Jeff YS Lover

A friend here has 2 different size of YS 4 str. engines. Both are trouble. Bigger one is ready to throw prop anytime (did many times) , smaller one is trouble to tune, both stop on air by chance . Strange systems we dont know how to play etc....

I had four YS engines at one time, and three months was about as long they were reliable, If you got two years you must have ran them five minutes a year. I used the correct fuel tuned them well and they just weren't reliable. I sold them all in one lump for the price of one.

Jeff,

I'm a YS lover too, I have five of them! Once you taste the brute power, instant throttle response and a needle valve that rarely gets touched, you wont be happy with anything else. I've tried several Saitos and other brands, and though they ran great, I was always disappointed in their power. For a YS, run 30% or 20-20 fuel, OS F plug, prop it to run in the proper rpm range and it will be happy. If it's throwing props, it's too lean. Oh, and another big plus, the fuel system allows you to place the fuel tank anywhere you want.

RS

I knew I woould hear a lot of negativity, but I have noticed that some people have engine problems no matter what engine it is. I just don't think a brand could survive this market and continue to build an inferior product. When i tune my engines I do not try to get every last bit out of it and I make sure it leaves a nice smoke trail. You guys that are having so many problems just hit me up with a good price and I will take them off your hands.

Only one member at my club runs them. Two other guys had them and they gave those guys fits. One spent a fortune sending his back to YS. The guy running them has a lot of them.

For me the turn-off for YS is that they require higher nitro fuel and that they require routine maintenance. By contrast, my Enyas and Saitos run well on 10% or less and require just about zero maintenance. But still, I hope to try one some day. I have had my eye on YS for years.

BLW, don't you find thst a bit funny that one guy has very few problems and the other spends lots of money and still can't get his to run. JPMacG, give one a try an you will love it, but follow the instructions and run it a bit rich. I have 12 in use and have never done any routine maintenance. I check the valve lash when I get around to it. What routine maintenanece are you talking about?
The operators manual says nothing about routine maintenance.

:confused:

I don't know of any routine maintenance, Check and Re-Set the valves once a year if needed and make sure I run them dry when storing. Don't use any mineral after run oils.
I have picked up a couple of YS engines due to the fact the previous owners could not get them to run correctly, maybe a diaphragm but mostly needle settings had them running like a Swiss watch.
Any time that any engine is throwing props as a rule they are to lean.

I have to run 20-30% nitro in my 3.3-4.6cc car engines, I'd not want a 20cc engine sucking that much nitro. Pure nitro is expensive! Car engines run 7-9min on 4oz, a 20cc 4C will suck 4oz in about 3.5 minutes. My Enyas run great on straight fuel 80/20, but have a wider needle on 5-10% nitro. 30% nitro probably burns 1.5-1.75oz/min. That's just too rich for my blood. No YS or Saitos for me. Ever.

That is good news. I heard that the seals / diaphragms or some other flexible parts need to be replaced periodically, like every 3 years or so. Happy to hear that is not true.

I forgot that we once had a helicopter guy who had a YS that ran well. His dad was sponsored by Futaba and others, so he always had the best of the best setups.

How about the OS pumped 4-strokes? They don't have the high nitro requirement.

I just picked up a YS FZ110 and although I have not run it, it appears to be of top notch quality. It will power my 60 size TF P 47 ARF which should be a lot of fun.

OS four strokes are super reliable. I bought a FS120 that is 12 years old and brand new mounted on a plane. I primed it and it started on the first flip...it has been running like a swiss watch even since with regular 15% nitro

Read this web site and follow the instructions for setup and operation of YS 4-strokes. The main thing is people do not understand the operation and try to adjust the carb like other 4-strokes.

http://www.geistware.com/rcmodeling/...er/ys_main.htm

My only YS is a 120 SF that my dad got for a Goldberg Extra when I was 16. I am now 36 and I'm flying a new Golberg extra, our third between my dad and me. I can't recall a single deadstick in 20 years. I made the mistake of using afterrun oil, so I had to get a new diaphragm for the pump and a new intake tube after crashing the second extra, but that's it. No engine has been so reliable or so powerful.

YS are the best four stroke engines on the market. The people that have problems, simply don't take the time to learn how to tune and run them correctly. I ran a DZ160 flying pattern for 10 years and 100's of flights. In that time i had 2 dead sticks. One was the plug failed and the other was from a piece of silicon fuel tube blocking the needle valve.

The only maintenance was to adjust the tappets and occasionally to replace O rings.

I've had 13 of which i still have 11, ranging from the FZ63 to the DZ175cdi in my current pattern ships. I also have 2 x DZ185cdi's on order and am waiting for the DZ70cdi to be released.

YS's love nitro, especially the DZ range which are a high performance engine. Never run them lean as that is the reason they throw props.

People complain about the price, but if you want performance you can't go past them. Saitos and Magnums etc. are just your every day run of the mill engines that give average performance.

GO YS!!

Drac 1, says it all! I did not start this to try to convert anyone over to YS, but to see the responses to my remarks on how I feel about them. I knew that they were expensive to operate going in, and I know that they will probably always be expensive to operate, but the distinctive sound and the unmatched power keep me coming back for more. I take no issue with any of the other engine makers, as they are great quality or they wouldn't last in this market.


Jeff

i have the ys 140. had some problems the first couple of tanks. the spring was on the wrong side of the pump diaphram. after fixing that. it's had 6 plus gallons of fuel thru it. the only thing that i've done is adjust the valves. it still pulls great. would i buy another? yes. it's not a pnp motor you have to learn it. every motor is just alittle bit different,

I have 2 YS 91s, an AC and a FZ, one dates back to early 90's and one to late 90's. Also have a FZ140 dates back to 1998 and a YS110 basically new. I consider them the best of any engines I know of. Extremely reliable, very long lasting, and long on power. Set it and forget it. If something changes, then service the regulator, check the valve clearance, and if this doesn't solve the problem, send it back to YS in Las Vegas. So far that has happened twice to me since 1998 that I could not resolve the problem. Do not screw with the tuning after each flight as it only confuses the issue. I rate them as the absolute best, with older OS engines close behind in reliability, but without the massive power output and the longevity is truly amazing based on my experiences.

I wish they still made the 2 strokes!

A little off topic but related. A YS muffler worked for me to quiet an old, Testor Series 21 .40 Black Head CL engine without significant power loss. Combination is a little heavy, but on the right CL plane (preferably a pre-1950's ignition CL) should work really fine. :D
http://www.rcuniverse.com/forum/atta...mentid=1943519
http://www.rcuniverse.com/forum/atta...mentid=1943520

I only have experience with the YS pattern engines, but they were great. My buddies flying the YS 2 strokes in helis swear by them, particularly in the .61 and .91 sizes for their power and reliability.

I have two in my heli's but I seldom fly heli anymore. Think I like heli's but love planes. With the 185cdi hitting the market, the 30cc arena has a new player in the game. Gotta have me one of those 185cdi motors.