bsumpter

Hey everyone!

I have a YS 63 that has about 1/2 gallon of Wildcat 20/20 fuel through it. It was broken in per the YS instructions with a MA 12x6 prop, and the valves have been adjusted to .003 two times so far. The engine is mounted on an UltraStick 40 (stock mount), and does a fair job of hauling it around.

I've noticed at high revs when there is a load on the engine (vertical climbs, loops, etc), I can hear a "clatter" from the engine. It sounds like valve clatter, or pre-ignition. It only does this at high revs, and only when there is a load on the engine. This is confusing me, as I'm sure the valves are within spec and I've done everything as per the instructions and from info gained here on RCU.

Other than the disturbing noises, the engine runs like a top. It has an incredibly low idle that is the envy of my buddy who primarily flys Saito engines. I am not getting the performance out of the engine that everyone here says they are getting, but this could be where I don't have a lot of run time on it yet. I get about 10,400 from an APC 12x7 prop. From what I've been reading everyone else is in the 11,500 range with this prop.

Any ideas? Think I've gotten a bum engine? Am I just being impatient and need to allow more run time? And finally, is the clattering sound normal for a new YS 63?

All suggestions appreciated.

Thanks!

Brian

Waco Driver

You will not hear noise caused by excessive valve lash on any 4 stroke model engine over the exhaust noise. What you are hearing is detonation due to lean mixture and/or overheating, excessive prop load, excessive nitro. My experience with a friend's YS 63 is that one clik too lean even on 5% nitro fuel will cause detonation.

ChuckAuger

My Feedback: (12)

I agree...my YS's sound like little machine guns at even a little lean. Richen it up a little before the chattering becomes clunking IMHO.

However...more nitro will usually help instead of make it worse. This sounds counter-intuitive, but seems to work. I think you ought to be able to swing a 12X7 with 20/20 fuel.

Another thing to remember is that this 20% oil is more than other 4-stroke fuel..I set mine to where they smoke like a little smoke system.

w8ye

My Feedback: (16)

Unless You follow Chuck and Waco's advice, the next stage is that the engine will backfire and ruin the prop and spinner, if you ever even find them, and your plane is going to dead stick.

Enjoy

Jim

bsumpter

I certainly don't mind richening it up, but if I go much richer it starts running poorly. When I richen it up to where the clattering sound goes away, I'm only getting around 8000 - 9000 RPM on the 12x7 prop. I'm not even sure it will fly the Ultrastick at this power level. What does everyone else with the YS63 get on the 12x7 prop?

I also posted this question in the manufactuers support forum, and you can read Dave's response here:

http://www.rcuniverse.com/showthread...readid=1032631

So should I consider sending this engine back to YS? Am I expecting too much performance from an engine with such a small amount of run-time? How long did everyone have to run their YS before the performance level was up to par??

David Cutler

I bet the chattering sound is the YS lovers in the pits chatting about how nice your YS engine is. YS owners do that.



-David C.

djlyon

Like the other guys said Bsumpter, you're lean. Mine turns a 13/6 apc at 10800. If you only incounter this going vertical and you have to richen it to 9000 to get rid of it then I think you may have a fuel dilevery problem or the wrong plug. Also wet fuel could cause this.

ChuckAuger

My Feedback: (12)

Well, I'm not going to go against Dave's advice. Much like w8ye, mine will kick a prop shortly after I hear this sound..sometimes before I can throttle back/richen the needle. I've thrown a prop in the air after only the slightest hint of detonation.

I guess if yours keeps running it might be something different.

I've never run a 12X7 on a .63. I got mid 10's on a 13x6, 11 on a 13X5.

David Cutler

My YS110 started to do that when I moved from a 15x8 to a 16x6.

Do you reckon I could solve it by just richening it up a bit, or have I over-propped it?

-David C.

bsumpter

Fuel delivery to the engine seems fine -- I can't say for sure once it gets inside the engine itself. I've tried both the OS-F plugs and am currently running a YS 4-stroke plug in it (looks identical to the OS-F). The fuel is brand new Wildcat 20/20 YS blend (just popped the carton). Oh, and this engine has never thrown a prop. It's never even kicked back any at all. I can slam it from idle to wide open, and after a few seconds drop it straight back to idle and it transitions perfectly.

I broke the engine in on 30% Coolpower heli fuel, as it was all I had on hand when I was doing the break-in. I don't seem to remember it doing that while running the CoolPower. But of course I was running pretty rich during that break-in period so that could explain why I didn't notice it until I got to the field with the 20/20 fuel.

I'll run a tank of the Cool Power through it tonight and see if it solves the problem. At least it'll let me rule out the fuel issue either way.

Thanks for the suggestions, guys! I'm interested in everyone's opinion who has experience with this issue, so if you have some insight, please continue to share.

Thanks again,

Brian

bsumpter

I actually shot a video of the engine while i was breaking it in on the CoolPower, and after watching it again the noise was not there during the break-in procedure. It also seemed that I had much more power on the CP fuel (of course it is 30% rather than 20% nitro).

This is all leaning me towards something being wrong with the Wildcat fuel. I'll know for sure when I run a tank of CP through it tonight. I'll let everyone know.

If you actually want to watch a boring video of the YS break-in, you can get it at: http://rclibrary.com/vids/ys63final.mpg (18.3 mb). You'll note there is no detonation when using the Coolpower fuel. It just took talking it over with you guys to make me remember that.

Waco Driver

Something you may wish to try is the addition of 5% Acetone to your fuel as promoted in these forums by our OZ contributor "downunder". I have been experimenting with Acetone for the past year in my homebrew 2 and 4 stroke fuels and find that it completely eliminates detonation in my 4 strokes as well as smoothing both 2 and 4 strokes.

My tests have been with only 5% and 0% nitro fuels so I do not know how effective it is with the 20% plus fuels. Whereas 0% nitro fuel was unusable in my 4 strokes without Acetone, it runs quite acceptably for sport flying use with the addition of the Acetone. These trials have been on a variety of OS engines including OS 45 FSR, OS 60 FGP 2 strokes, OS 52 FS, OS 61 FS, OS 120 FS, OS 120 Twin four strokes.

JWN

My Feedback: (42)

I would be very leery of adding acetone to any fuel intended to be used in a YS or any other engine which silicone pumps. I would even like to see what affect, if any, it has on silicone fuel lines. As far as the video above, I noticed at the end the specs list shows a Fox Miracle plug. You might want to try an OS F plug. This is the plug Dave Shadel states must be run in the YS 4-strokes as it is the one they are happiest with.

John

bsumpter

I'm not running the Fox plug now. I ran it during break-in until my order of OS-F's and YS plugs made it in. I ran it the first time at the field with the OS-F, and thats when I noticed the "clatter" sound. I switched to the YS plug the last time at the field with no noticeable difference.

I was actually surprised that the Fox plug did as well as it did. I honestly only changed it because everyone suggested it -- it seemed to run fine with it. The OS-F and YS plugs do look "sturdier", however.

JWN

My Feedback: (42)

Interesting comparison on the Fox vs. OS/YS plug. I have an OS F plug in my .63 and it seems to be quite happy. I will keep your findings in mind though as I also have a NIP Fox M plug in my box.

BTW, the OS F and YS plugs are in fact the same plug per Dave Shadel. It looks like YS just wanted to get their name on a plug so they could make a few extra $'s on plug sales.

John

Sport_Pilot

You may not have pre-ignition but detonation from a plug that is too hot for the fuel, prop, and altitude. A Fox plug is a shade colder then the OS F. If you are running very high nitro fuel, like 30% or more, you should try the K&B 4C which is colder than the Fox. You will also save some fuel, you will have a richer mixture with a plug that is too hot, more power and better economy with a plug that is just right.

Funny but the longer Fox plug looks sturdier to me. Maybe the shiner chrome or nickle plating of the OS makes it look that way? The Fox plugs use a chrome-zinc plating that will allow it to rust if left in the rain. Only problem I have with Fox plugs.

w8ye

My Feedback: (16)

Bad fuel will be hard to needle. In fact, it will be impossible at idle and mid range. At high speed, the needle will act funny. The engine will sputter like the ignition is bad. You'll think it's rich. So you lean it out more. Then you're too lean.

I just ran a Y-S 91 with some bad Heli 30 yesterday. Couldn't set the low end to be perfect to save my neck. I then tried the fuel in a Magnum FS120 and it ran the same way. I had some Omega 10% setting around and they tuned right in.

Just because you just opened the box, doesn't mean that the fuel is fresh? Try some in another engine? The humidity in Enterprise, Ala must be close to 100% this year. Maybe it has water in it?

Enjoy,

Jim

FLYPAYSON-RCU

I am having the same problem with my 63-- I am running a zinger 13-6 with wildcat 20/20, only getting 9400 out of mine, and that is over on the lean side. Mine seems to idle fine but only momentaraly, it then seems to load up and die. I have leaned out the low end setting, which didnt do much. I am wondering if it is pumping too much fuel?????????? It seems to be spitting a small amount of fuel out of the carb during transition--- The manual says to start out around 2 1/2 turns on the high end for break in, I could not get it to run at all until I leaned it to just over one turn, where it ran, but still extremely rich. I am lost as to where to go with this thing next-------------- Any thoughts? Thanks , Travis

djlyon

Travis
The condition you have normally indicates your not being regulated.
* Check valve not working or in backwards. Dirt in the regulator so that the nipple is not seating or a torn diaphram.


It could also be the regulator screw is to far out.

Denis

FLYPAYSON-RCU

Hi Dennis- What are the odds the factory could have installed the check valve backwards? I just put this engine through the initial break in today, it was brand new---I looked at the regulator and it is flush with the body as per the manual. Should I disassemble it to check that the check valve is not backwards? Thanks, Travis

ChuckAuger

My Feedback: (12)

You have to install the check valve in the pressure line. There should be a sketch in your operating instructions showing the location and direction of flow of the check valve. It is not factory installed.

In short..you should be able to blow thru the check valve to the tank, but not from the tank to the engine.

And 2 1/2 turns is too far out in my experience..try about 1 3/4, but note, there is NO WAY to give turns in or out over the internet and have your engine run properly. Adjusting the needles is always required (not that you don't know this, but I see lots of posts looking for exact turns of the needle).

FLYPAYSON-RCU

I thought there may have been an internal check valve that was being referred to. The in line valve is correctly installed. I did try and adjust the needle valve in many different settings with no good outcome.Dirt is not a possibility, as this is a new engine with a new case of fuel. I just dont know....................

ChuckAuger

My Feedback: (12)

Never rule out any possibilities. New YS .63's have been known to have a piece of trash under the plunger...this will make one run pretty bad. I'd check all posibilities.

deputydog

Hey guys!
I did'nt see where it was stated that after a run when you released pressure from the tank that you heard a prominent hiss! As stated before, the clatter is from a lean mixture. Either the pressure is inadiquate or the reg has a problem!
My 63 is turning hi 11's with a 12x8 MA scimitar and a 14x4w apc. This last gallon was 30% because the lhs was out of YS20/20. I personally dont care for the wildcat fuel but it may work for you.
DONT add anything to the fuel and stay with the OS F or YS plug(same/same!) Since your valves are within limits it's time to go back to the basics. Check your fuel delivery system(tank, lines...).
I had a 91 that gave me fits like this and the tank was split at the stopper. it would hold 2psi but not 6!
Keep us informed.

djlyon

Travis

The check valve is not in the engine. It goes in the fuel line (tank vent line) between the engine and the tank. It looks like a fuel filter and is often mistaken for one. Without it in place and oriented properly nothing is going to happen properly.

Denis