Well, had a great time on my L last weekend. That was last weekend. I've still only got about 40 or 50 flights, not all successfull though, on this engine. But last weekend it ran great. This weekend has been a different story. Seems like it runs great for the first half tank, then, seems to lean out. It also has been pissing fuel out on the ground. Running or not. And yes, it's been vented. The story on this engine though is this; Bought about 3 or 4 years ago, wouldn't run for crap. Sent it back to ys, Rich replaced the piston and ring and I think sleeve. Something about a bad batch of pistons(warped). Well I've never had a good flight on it until last weekend, although, I really havent flown it hardly at all. But it ran great last weekend. Perfect. Well, story had changed this weekend as i said. Any ideas on why?

All I know is you are more tolerant than I am. I have no patience with an
engine that doesn't run right. For what they charge for these things the least
you should expect is for it to run as it should.

tommy s

I totally agree. It should run out of the box. I guess my opinion on that doesn't matter to much to YS though, lol. I'm ready to change to a 2 stroke now though. Had enough YS problems.

I love the way 4 strokes sound and the power they have in the verticals but I have
never liked tinkering with the engine just to get in a few flights on flight day. The
only thing I do occasionally with a 2 stroke is tweak the needle valve every now and
then. I am planning a new 2 meter pattern ship in the near future and will use a
Mintor 1.70

tommy s

Yeah, i think I might sell both my 140L's and buy a couple of mintor's myself. I do love the power also that my L's produce. Oh well, hope someone can help me and change my mind quick............

Power? The L is is weaker than the DZ, all four OS 2 strokes, probably both Mintors (I've never seen them), and the Webras. Wait a little longer and you can add a Hacker and the YS 160 to that list.

Whoa, this post wasn't about power. It's about a problem I'm having. But maybe you have tried the L with a lead sled or something. My L's pull my 10 1/2 pound planes without a second thought when they run right. Unlimited vertical. Of course the DZ is stronger. It's the new YS. Wait till they come out with a new one. It'll be stronger 2. Let me guess, you have a DZ? You shouldn't hate on people that don't want to run a DZ because of the problems they may have had with other ys's. That's why I don't and am considering going to a 2 stroke. I am also considering going to the Hacker also. And as far as the OS, It's got plenty of power also. You took me off of my own subject. Someone please give me an idea. I guess I'm just gonna take it apart and start looking for a problem.
Hey, I know who you are. I ordered 6- 9 g servo's from you a few weeks ago off of ebay. 2 of them that I have installed in a plane have already took a crap. I don't suppose the manufacturer warrenties them do they? Thanks

hi Patternflyer
change the regulator plunger.One of my 140l have the same problem.
Mirco

You will have to send back the problem servos, but yes, we will replace them. Getting bad ones back enables us to figure out why they went bad. Call toll-free for a Return Merchandise Authorization number (so we know what to do with the package when we receive it).

Whoa is right... it just sounded to me like you thought that the L had an advantage in power. I was just pointing out that there are at least seven other engines which out-pull the L, so power probably isn't a reason to hold onto that motor. If you don't need any more power and love the L's throttle authority, then you have a darn good reason for wanting to fly it (throttle authority is the primary reason to run a DZ as well).

And yes, I have two DZs, if it matters. I had two OS 140RXs prior.

Adam Glatt

Very carefully, so as not to lose parts, disassemble the regulator and give it a good cleaning and flush the little passages. Reassemble and try again. Your pissing fuel problem is 90% likely to be in the regulator. Ensure that the gaskets seat well. If that fails, check the head. Remove the head and check that the valves are not burned and that they do not have excessive side play in the guides. Side play wears the seat to the point where the head is not repairable and this happens quickly. Ensure all screws are gutentight, firm and then a little bit more is my method.

It really sounds like you simply have a stuck regulator due to debris, maladjustment, or bad diaphram.

What fuel are you running? I use only 30% Heli Coolpower. I pay about $42.00 per gallon here but it is the only fuel that gives consistent result run after run after run.

Mark

Did you check if your fuel tank is not leaking at the seam around the cap? I had that problem with one of my YS installations after about a couple of hundred flights. The leak allowed enough pressure for the plane to fly, till it got worse. A pressure check on the system revealed a slow leak, much more leakage under pressure. Also check the regulator as indicated by others here. I have 4Ls and they all run great. I run YS20/20 or CoolPower Pro Pattern 20 when I cannot get hold of YS20/20.

PineBaron

A buddy of mine had problems with his L also. Some other thoughts

1) On a flat surface with a piece of 600 grit sandpaper(or 300) sand the valve cover as it may be leaking air after the engine gets hot.

2) Try leak free gaskets. Have had good luck with these(don't know why YS won't change to them)

3) Get the instruction manual out and make sure the low end needle is set correctly and the regulator is flush with the top of the housing(These 2 things are what worked for my buddy)

4) The L only has about 2 clicks of appropriate high end adjustment. Anything outside this range, either rich or lean will result in a poor flight.

Once a 140 is set, it usually doesn't require many changes, other than a high end needle change for old glow plug or altitude change.

ed

Thanks everyone. Pulled the regulator out. Cleaned it real good. I didn't find anything that looked dirty, but who knows. Checked the valves. They look good also. Pulled the throttle barrel out. The rubber o ring had a part of it that was missing. Got two on order. One other thing I noticed was that when my throttle barrel goes to almost closed it gets tight to turn. I checked it with a flat straight edge. It doesn't appear warped. Don't know what I'll do about it. I may have to buy a new barrel. I also changed all fuel lines after checking the tank. They all looked fine and pressure tested fine. But I figure it couldn't hurt to change em. Just waiting for Central to send the o rings now. I'll post if any of this worked. Thanks for the help. Chris

Patternflyer1,

You have gotten great tips from the YS user community on troubleshooting your L's running condition. Have you tried posting this condition in the YS forum? There you will receive responses directly from Dave Shadel of YS Performance the US importer and service center for YS motors. I have provided the link below to the RCU YS Forum.

http://www.rcuniverse.com/forum/YS_E...mid_197/tt.htm

On the pressurized YS systems not a DZ style motor......

There are basically 2 reasons it will leak fuel.

#1 Regulator not sealing..... ...possibles are


.....this could be dirt and debris in the reg (Very common) Use good filters
.....too much pressure in tank
.....not enough spring pressure caused by a damaged spring
.... deformed diaphragm (common when the motors set for long periods of time.)
..... hole in the diaphragm
..... plunger not seated due to a mold nipple or deformed cone shape end.

#2 problem with leakage is an air leak. This lets the regulator not have good pressure to hole it closed.

.....Valve cover gasket (very common)
.....Regulator gasket (very common)
.....head gasket ( the thin metal shim, not very common but check the bolts for tight)
.....carb and pack plate gaskets ( again not common but if they are not seated damaged or not tight it could cause leakage)


I would say #1 fix is to make sure its all clean. Look at the spring for damage, look at the diaphragm to see its not deformed, the plunger might take a magnifying glass to inspect.I use a can of compressed air to blow the reg parts out. If all the parts look OK they probably are fine...you'll know a problem when you see it. Then change the reg gasket.

Take the valve cover off and "face" the mating surface on a piece of glass with some 600 grit paper...Sometimes the painted surface becomes slight uneven....If you hang the nipple on the bottom of the valve cover over the edge of a piece of glass and slowly rub the mating surface on the 600 grit with a glass as a flat surface...you can take the paint off the valve cover.....if you go slowly and check your progress often you'll see where it was not flat.

So far your total investment is a set of gaskets.....Then stick it all back to together.

and try it out.....Oh note the reg body has a nipple on the case....a directional mark if you will. This protrusion goes facing forward. If it is turned toward the back the motor will leak like crazy. It might still run but not well.



Troy Newman
Team JR

I had a similiar problem with a 120AC that I bought used. Replaced ALL the orings($20) and its as good as new now. Also ditto on all the regulator suggestions(especially about the *** pointing to the front!). Good luck!

Thanks for all the replies. Sorry I never got back to say thanks, I'm going through chemo right now and feel pretty crappy. Troy, Thanks for the perfect advice post once again on my 140L question!!!!!!! This is the second time you have spent your time helping me. I appreciate it greatly

Well just wanted to thank everyone again. Troy had it when he said to make sure the nipple is facing forward. It was facing to the rear. Man how did I miss that one? I guess its simple. Adjusted the valves last night and started it on the ground at home. Sounded awesome. Can't wait to go fly tomorrow. Thanks again Troy!!!!!!!!!!!!

Troy,

Where can I get leak free gaskets for a ys 63 ?
Its almost new, should I change the gaskets to leak free and avoid problems down the road ?

Is there a preventative periodic maintenance checklist for YS engines ?
I would hate to start experiencing some of the mystery troubles.

Thanks,

L

Leak Free gaskets are not available for the 63.

Yamada has changed the gaskets and the problems we had with the old paper gaskets is not a problem on current motors. The deal was original gaskets were fine they just were a thinner paper material. And the fuel would cause the edges to swell. The newer gaskets don't do this.

I don't see a real big need for the Leak free gaskets on more current motors.

As for problems and care and feeding. I recommend a good fuel, and run the motor dry when its going to set for a while. Once run dry use some Ultra Oil from Performance Specialties. I know of some people that use Mobile 1 synthetic...but I don't use it. I use the stuff that Dave Shadel sells and has sold for many many years for the YS motors.

Run a YS or OS #F glow plug.

Next is good fuel filters..when the motor gives problems look to the filter first. I filter my fuel 3 times before it gets to the motor. I have a filter in the bottom of my jug, one after my fuel pump, These are both before fuel enters the models system. Then I have one in the plane before the motor.

Next care and feeding item : DO not put big props on them and load them down. Run the motors in the recommended RPM range. The 120-140-160 motors like about 8300-8600rpm....The 110 and 91's like around 9000...And the 53/63's like around 10,500

If you prop the motor to run in this range you will have a strong powerful performance and less problems with the motor down the road. Over rev them or load them down really hard and you'll have troubles.

Next is fuel. I know some like 15%. This is not the best fuel for a 4 stroke motor. Even if you are just sport flying the motor will be easier to set mixture and perform better on 20-25-30% nitro. I run Cool Power 30% Heli fuel in all my YS motors. It is a great fuel. I have had zero fuel problems since I started running it. Lots of good fuels out there...but when you have trouble look to the Cool Power as the standard. Sometimes a fuel problem is simple to find but we ignore it. THe answer of I have used XXX fuel for 10 years and never had a problem. Well go buy a jug of something else and try it. Morgan really has a loyal following. The reason is they have a great product that is available almost everywhere!

The Cool Power 20-25-30% pro-pattern fuels are good too. Don't run Castor oil in them and always set the needle valve about 200-400 rpms rich of peak. Use a tach to set it up. Make slow movements on the needle as the changes may take 5-10 secs to happen. The mixture has to travel a long way to the piston from the needle valve...So make slow changes and wait for the response.


Most problems I have seen with YS motors are:

#1 Dirt
#2 poor choice of fuel
#3 too big of prop or too small of prop
#4 Lean
#5 Glow plug (YS or OS #F) no other plug is as good.




They are really the best glow motors on the market today.

Troy Newman
YS Performance Field Rep.

What are Leak Free gaskets and where can I buy them for my YS 91?

Troy, when you say CoolPower 30% heli fuel, do you mean the blend with 22% low-viscosity oil as listed on the Morgan fuel site? http://www.morganfuel.com/cp_blends.htm
My local dealer sells this blend but for some reason they claim it has only 18% oil so I've not been buying it. The dealer is probably wrong though unless there are two types of CP 30% heli blends. No oil percentage is listed on the jugs that I've seen.

Please note that Troy has not responded to this thread since 2004.

ooops, bugger I completely missed the dates :-) The leak-free gasket question bumped it to the top again, I thought it was odd someone asking about L engines in this day and age [&:]

Troy can't post on RCU anymore, try sending him a message from his website if you want to talk to him. www.patternflyer.com/troy


Chris