I changed my mind, I went with a few peoples recommendations and bought the UCD60. I was recommended (by the owner of the model shop) that an OS FX 90 (2 Stroke) would go well in the model but I really wanted to use a 4 stroke engine for the first time.

In order to get comparable power to the OS FX90 (2 Stroke) would I have to go as big as an FS 120 SURPASS Mk.lll (4 stroke) or would a FS 90 Four stroke suffice?

The difference in weight between the OSFX90 (550gms) and the FS 120 SURPASS Mk.lll (920gms) is 370 grams. Would this make much difference?

Thanks.

I have one with the YS110 , its an awsume combo . Perfect i wud say . if u use the 2stroke fx90 ull have flooding probs cause the tank is much higher than the venturi . better use a pumped 4stroke like the os90 fs11 surpass , its a pumped 4strk from os and is also a very good combo for this kit also u can mount the tank over the CG by using these motors , a compromise wud b mounting the 2strk os90fx sideways . to avoid flooding\midrange loading up. the 120 is unnessary cause the 90 anyways does the job at half throttle.

Thanks Yoga.

Any ideas where I can get one in the UK? Have read that the OS91Surpass can be slightly sluggish for more aggressive 3D but I am pretty sure it will be more than adequate for me. Would just like to make sure that's all!

(I noticed you are in India as I was in Goa back in March as I have a friend whos parents live there 6 months of the year! Where are you?)

I have just visited my local model shop, they said they don't stock YS engines anymore. When I asked about the YS110 they naturally spoke poorly of it saying "when it goes well it goes really well and when it goes back it's a nightmare, the OS provides nearly the same performance but with a lot more reliability and user friendliness"!

I think I am going to stick with the OS90....!

I am sooo confused!

Hi:

I second the YS 110 in the UCD 60, mine is just great. Bottom line with the YS is its a great engine, period. People who have problems with them typically do not follow simple instructilons regarding the care and maintenance of the engine. Nothing unusual. Use the correct fuel and oil, in line filter and keep the valves adjusted, once after breakin and once a year. Have had around 10 of them through the years, never a problem. Best 4 banger out there, period. Best power by far, best throttle response, idle etc. Break in correctly, take the time to set idle and throttle correctly and fly foreaver. If someone bad mouths a YS, its because they are one of the clutz out there that will screw up any engine, even a 2 stroke. Never fails. (The guy that adjusts his needle after every flight, and never gets it quite right). You do not have to run the 20/20 fuel, I rely on 15% power Master for everythilng I run includilng Jett pylon engines. Must have the 20% oil. The OS is a just ok engine in my book, no longer have anything to do with them since their continueing screw ups on cylinder pealilng which still is not good. Any engine builder who sells on the high end and does not build them correctly does not deserve your backing. Many of the much less expensive engilnes such as Thunder Tiger and, Magnum, Super Tiger do it correctly and do not attempt to save 50 cents by reducilng the number of head bolts, or bearing quality. If you really want a outstanding 2 stroke engine, spend the money on a Sports Jett. Yea, costs twice as much and worth every penny. My Jett 35 is on its 4th club raceilng season, my 50 on its 3rd. Just keep getting better each year rather than falling off. Figure it out, they are my least expensive engines of all the 2 strokes based on performance and longevity. ENJOY

I had the OS 91FS Surpass in mine and it was plenty for everything but hovering. It just flat was not enough power to hold it in a hover and it certaily will not pull out. I am at sea level and the engine ran perfect. I switched to a Saito 1.20 and that was better. I agree that the YS 1.10 is an absolutely perfect engine for the UCD.

Another great engine would be the Saito 125. Especially if you are near sea level. It saves a few ozs as well, over the YS.

Thanks
Barry

Does the 125 require a pump if you want to put the tank on the CG???

Yogafly and remenke.

Can you confirm this is the engine.......

http://www.probuild-uk.co.uk/product...11&subCatID=19

The os appealed becasue it was low maintenance but will have to get some reading in...can you point me to any good articles on the ys110 on the net?

http://www.centralhobbies.com/Engine...tm#YS%20FZ-110

http://www.ohiomodelplanes.com/ysengines/

http://www.chiefaircraft.com/rcmsec/...nes/YS/YS.html

All appear to have them in stock.

OH, here are a couple in the UK

http://www.probuild-uk.co.uk/product...11&subCatID=19

http://www.rc-aerobatics.co.uk/patternengines.htm

Plus I think there is one for sale in the RCU classifieds.

Thank you Mike.....

Any good articles on the net about maintenace...I'm fearing I am a "clutz" (Rmenke - what ever that is). :-)

YS engines are easy to take care of. At www.centralhobbies.com there may be some stuff on maintenance, also the pattern forum here on RCU has some really truly knowledgeable YS guys.

They really require nothing different than a typical 4 stroke. Just set the pressure regulator screw (Big Brass Screw underneath) flush with the engine case and it will be fine. After that its no different than any other 4 stroke. Just the occasional valve adjustment which is super easy if you just follow the instructions that come with the engine. I dont check my valves but about 1 time every 50 flights or so and then I usually do not have to readjust.


It should be this way from the factory anyway. I fly pattern and we are constantly around lots of YS engines. I see needle valve adjustments, occasional plugged check valves/fuel filters in the fuel lines( which can cause it to go lean, remember to check your check valve and fuel filter anytime the engine seems to be leaning out) problems due to bad fuel and heat issues when it gets above 95F outside, but never is the pressure regulator a problem.

Sometimes you may get a little trash in the regulator, but rarely. All you do is note the position of the adjustment screw, remove it and clean up the regulator parts and the little port. Then put it back just like it was and go fly.

All that being said, I have 2 1.40 sports and a 1.60DZ. Now that they are set (after break in) I never touch the needles or anything unless its to richen it up slightly on a really hot day.
They really do run great and make a ton of power.

Mike East...

Ha, Ha. That's a good one about the YS engines. I agree they are very powerful and excellent running engines. But, I think they are difficult to get "right". And...the regulator makes a tremendous difference. To say the regulator is never a problem is a kin to saying "the check is in the mail".

I love my YS engines, and in certain cases I wouldn't run anything else. However...I believe they are difficult to tune.

Ahhhhhh....YS, ya love 'em till you don't.

Thanks
Barry

[8D] I honestly have never had any problems with the regulator setting. It has always been flush it up with the lip of the flange and forget it. We have no problems getting 8400-8600 RPMs on a 16x11 or 15x12N or 17x10 with the sports. I am bing totally honest when I tell you that barring fuel quality, plugged fuel/vent line issues they just run.. They really really do for us. We are at sea level, but it gets extremly hot and humid here in SE Texas.

I ran an OS 91 on mine. Flew it fine with 16x4W APC, but no hovering maneuvers. Another guy at the field has one with a pumped OS 91 and 14x6MA. Again flies fine, but won't hover. I agree with all who have suggested the YS--great power. The Saito 125 should be OK too. No worries with inverted engines--just have to adjust low end.

Greg

mikeeast...

I think the 110s (that's what I have) are the worst for adjustment. The engine is pumped up pretty good. I love the way they fly but I spend 6 months of my life that I'll never get back trying to make them work. I finally just kept opening the regulator until I got it tolerable. Then adjusted from there. I had to open the regulator to 3 turns. (flush was about 2) This finally kept them from deadsticking. Now, I'm very impressed. But, just the other day one started giving me problems. The diaphram was shot. I replaced it but couldn't make it work. I sent it in for repair. Turned out I had installed the cover on backwards. It's difficult to tell on those engines.

I would recommend them to people who have 4 stroke experience, but for the first timer or someone who doesn't like to fiddle a bit to get them right, no way.

Anyways...I love the engine but they're not for everybody. For a long time I didn't think they were for me.

Thanks
Barry

We have two flying in our club....one with a Saito 125 and the other with the new OS 125. Both are very good choices, but neither is as powerful as a YS

What new OS125? I haven't heard of that. Sounds interesting.

Thanks
Barry

MY BAD....it was an OS 120AX, not a 125 (wishful thinking?).....too bad it replaced the 1.08 which I dearly loved!

Hmmm.....I'm happy with the FA100 in my UCD60. More than enough power for all 3D maneuvers. 15% coolpower APC15x4W

Do not believe that os bul.**** about the 91 fx weighing 550 grams. When I put mine on a digitale scale it shows 770 grams. Not much difference after all then.Not even without muffler weighs it 550 as the muffler is 185 grams. Maybe os weigh their engines without muffler and plug(who use them anyway) and fill the engine with helium right before the weigh in[sm=lol.gif]

I had one of these with an OS .91 4stroke, that was a very good combo, IF I ever did another one, I would use a SAITO 1.0 for somewhat better vertical pullout from a hover, 15% fuel 15X6 prop..

The YS110 is the perfect engine for this. My UCD 60 has an old YS91AC, and it hovers at just above half throttle. As to the issue of YS engines being difficult to tune - I don't agree with that but I also know why some people say it. I've flown YS for over 14 years and I own 12 YS engines from 63 to DZ, and I used to swear at that 110 like no other. Then I read a thread saying to open the regulator to 3 turns (well out past flush). I did that and all the problems disappeared. Just use an aluminum spinner (or at least one with an aluminum backplate), use at least 20% nitro, don't throttle up suddenly when it is cold, and read the directions. Once you get one of these set up right, it will reward you from then on.

Had an O.S. 91FX and it flew great. Ran a 15x4W prop from APC which was the best setup for the motor. Plenty of power for hover and pulling out. No, it didn't accelerate to 100 MPH straight up, but it had greater thrust than weight.

The YS 1.10 is much stronger than the OS 1.20. The OS.91 pumped isn't even in the contest and their trouble record is far worse than the YS 1.10. High performance flying is a costly adventure, unfortunately.

A Saito 1.25 would be a better choice than any OS four-stroke. It is very light, relatively speaking. Combine this with the Cline or Iron Bay regulator that you will need and you could have paid for a YS 1.10.

If you want a powerful set up for cheap, get a Super Tigre G90, a Magnum 90-108 or Perry carb and a Cline or Iron Bay regulator. Lots of power and reliability (after tossing the ST glow plug), will last a long, long time and you'll have no valves to adjust. Another plus is that it will run happily on 5% nitro fuel. Just my $.02.