YS engines?
 

I wanted some input and suggestions on YS engines. I have a 61fx in my minnow now but was thinking of putting that in my BH models t-28 trojan and put in a supercharged engine in the minnow, any suggestions to what size and any input on quality of the engines, tuning as that is my main concern since supercharges make any engine harder to tune. Thanks alot.

RE: YS engines?
 

They really arn't super charged, I figured that was the term used for lack of any better way to describe them?? I would say they are the best four strokes on the market. They tune the same way as any other four stroke. There is one extra screw on the bottom of the engine, a big brass screw, it just adjusts the ammount of pressure and for the most part it is factory set and almost never needs adjustment.

RE: YS engines?
 

The YS 63-S would go well with the Minnow. YS engines are not more difficult to tune, they just run a little differently.

http://www.centralhobbies.com/Engines/ys/YS63s.html

RE: YS engines?
 

Ok I see what you mean, now I would imagine that screw would change compression? Thanks for the advice on the engine opinion I will look into that one right now....Thanks again...

RE: YS engines?
 

All I know is that the YS-63 I just bought runs like a striped a** ape.

RE: YS engines?
 

No, that screw just adjusts how much pressure is going into the fuel tank. Why don't you just pull up YS and read the instructions, they will tell you pretty much anything you want to know.

RE: YS engines?
 

YS engines do put out a lot of power, more than most other engines their size. However, there are a few things that need to be taken into account. Fuel, YS engines really don't live well on low nitro content fuel. In fact, they LOVE nitro... Lots of nitro. The more the better. I run 25% in my YS. Maintenance. There is one thing that you MUST do on a YS engine, or you won't fly. You have to periodically check the diaphram on the fuel pump, and replace it at the first sign of wear. If that diaphram cracks the engine stops running.

Dont' get me wrong, I LOVE YS engines. I just wish I could afford more of them. I have a YS 120 that is waiting to go into an Ultra Sport 1000 if I can ever find time to get the kit on one of my building boards!

Ken

RE: YS engines?
 

And my YS engines don't know the difference between 15% and 30%, they all run great on 15% and that's what they get.
I always have a diaphram on hand just in case but I have never found any way to check one for wear, it either works or it doesn't. So far I have changed one in a 1.10 after five years of use and one in a 1.20NC after countless years. That engine was put up wet for three years and when I installed it into a plane I had to replace the diaphram. The 1.10 was working fine one day and not the next but there was no mistaking what it was. Two screws and a new one and off it went. I didn't have any old style units for the NC and tried one of the new ones for a 1.10. That didn't work at all and I had to break down and buy the correct one and a gasket. Installed the correct parts and it's back in the air. I have had a lot more problems with my OS pumpers and OS will not sell you a regulator diaphram, they want you to send in the engine and they will deduce if it needs a new part or new carb. With the prices what they are today I can't see anyone buying anything but the YS four strokes. If anyone has access to the OS diaphrams please let me know. It bothers me to think OS can't just sell me a two dollar part.

RE: YS engines?
 

I have a YS .63. It hauls some serious MULE. That engine YANKS my Giles 202 50 off the ground like it was rocket powered. Lots of power.

My YS does not tune any different then my Magnum 91fs, O.S. 70fs, Saito 1.20fs. Now my YS has close to the power of my .91. So far, knock on wood, I have not had the diaphragm tear or crack. It has been a tune and forget for a month engine. The needle does not need tweaking at all.

Go YS and have fun. I picked mine up from Chief Aircraft.


Dru.

RE: YS engines?
 

I've got 2 YS engines. One is a 91 AC and the other is a 91 FZ. I got the 91 AC NIB. It took time to get it broke in but since then it is a powerhouse. I
installed the 91 AC in my World Models P-51 Mustang. It flies around with authority at 1/2 throttle. I had a Thunder Tiger F-91S in a Great Planes Big Stik.
It flew good and had good power but when the exhaust pipe broke I pulled the engine. I installed the YS 91 FZ. The FZ had so much power that it took off
at 3/4 throttle and flew around with authority just off an idle. I've never pulled these planes at full thottle because I was afraid to do serious damage to the flight controls.

RE: YS engines?
 

Thank you all, you talked me into it, I think I will go with the YS 63s in my minnow and see how she fly's. And they are a bit pricey but if you say they are worth it I trust your opinions. I got the new cowl and engine mount for the minnow after taking out the super tigre. So just gotta order the engine. So 15% will be ok? Thanks fellas...

RE: YS engines?
 

I have a 1.10 in a Mid West 60 size Hots, my goodness!!! I had one in my Bridi 60 size Kaos!! Oh MY!!! I have a 1.20 in a CG 60 size Extra, talk about getting with the program!! I have some older engines under the bench just waiting for a home. I just love those engines!!:D

RE: YS engines?
 

My brother inlaw had a YS....I think it was a 91, but I don't recall.....he spent about a year trying to get it to run correctly.....and it went back to YS for "repairs" on 2 seperate occasions....He finally sold it on Ebay and just last week bought a Saito 125....

RE: YS engines?
 

We I know a guy who bought a YS .91 from someone else who could never get it to run right. The new owner just hooked up the fuel lines correctly and it runs beautifully.

I too heard the horror stories and stayed away from YS until I finally just got one one not too long ago. Now I own two. If I build another glow airplane, I will likely own another as well.

As for price, they are priced similar to and possibly even less in some cases than comparable 4-strokes from Saito and OS.

RE: YS engines?
 

YS engines actually are supercharged - they use direct shaft work to compress air intake. Compressed air has more mass per unit volume, and thus more fuel can be stuffed in the combustion chamber leading to greater power output. YS also uses a pressurized fuel system to keep the mix in balance.

I have yet to run my YS, but having an understanding of the system I do know that preventing and repairing any leaks is doubly important.

The power and sound of a YS are pretty amazing, and I find the inner workings of the machine to be thermodynamically sweet;)

RE: YS engines?
 

Thank you all, I just ordered my YS for my minnow, once I install it I will let you all know how I like it. Thanks for the help, it is appreciated.

RE: YS engines?
 

Are you using the YS63 for the Great Planes Minnow? The 63" plane? If its that plane, I thought it would balance better with a 60/90 sized engine. I am thinking of getting that ...

RE: YS engines?
 

I didn't want to be the one to say it. The above information is absolutely correct. The air intake is actually compressed. More air creates the ability to use more fuel while maintaining the proper burn ratio.

RE: YS engines?
 

That is true but when someone is thinking of super charged they think right away of a blower of some kind sitting on the top of the engine. I look at the YS as more of an injection system then a super charger. Call it what you will, they get with the program.

RE: YS engines?
 

Even if it isn't a typical "supercharger" like a belt driven, exhaust driven, etc. they definitely have a higher volumetric efficiency than modt 4-strokes and tons of power. What I've been impressed with is the pressurized fuel system. It actually makes tuning a little easier in my opinion and it seems to be more consistent.

RE: YS engines?
 

I was on the fence about what engine to get for my newest plane, and once I read how the whole system works I was hooked. I just spent two semesters talking about 'piston-cylinder devices' and superchargers in thermodynamics, and found justification in spending nearly $400 on a model plane engine due to the fact that it's exactly what I'm studying in school.

I guess there are lots of ways to supercharge an engine, but they all have one thing in common - using shaft work (via a belt, the crank shaft, gear train, whatever) to drive a compressor, compress air and force it in to the combustion chamber.

What I love about the unit is the simplicity; instead of using a breather valve in the space under the piston, they added a rotary valve to the crank shaft and use the bottom side of the piston to compress air. The valve opens to let air in, the piston compresses the air, and the valve opens to let the compressed air into the 'mixing chamber' on the back of the engine where it mixes with pressurized fuel. There are basically no extra moving parts, and energy that is normally wasted transferring air in and out of the breather is used to create more usable energy.

RE: YS engines?
 

Joe

Did you ACE you mid-terms?

RE: YS engines?
 

Not sure, but I'm sort of on Spring Break =)

RE: YS engines?
 

I have built a few engines with blowers but when I started playing with the turbo chargers I liked the idea a lot better other then the little lag time, no need for energy to make horse power. It would be cool to make up a system on a V-8 like the YS has just for fun. All but one of my four strokes are pumpers of one type or another, OS or YS. The prices of the OS now make the YS look even better. One of the key features is aircraft set up. With a pumper you can put the fuel tank dead center or a bit forward of center over the CG so there is almost no weight shift as fuel is drawn down. As to that pressureized fuel system, oh what fun it is to squirt your friends in the next pit, not to mention when you forget and release the wrong line after a flight. What YS person hasn't done that??:D

RE: YS engines?
 

The YS bath is always fun! :D