mpalermo

I am new to 4 strokes so this is where most of my issues lie.

I just cannot get it to run when I change throttle position when I take it from about 40% to WOT it just stops and fuel flows out from the carb.

I have the needle set as per the instructions to 1.5 turns and it is leaving a very nice smoke trail so I do not think it is running lean.

I remember another post where I have seen a backplate like this but I cannot find it, I believe the issue there it was backfiring and it could not be heard, I believe I am having the same issue here.

I am using a tru turn spinner with a double jam nut and after the run the prop is loose.

Any thoughts would be greatly appriacted.


(I will upload images later I am having problems getting it to wrok from this computer)

(edit, looks like I got it to work!!)

rcdude7

My Feedback: (264)

I am not a YS expert, but I do have a .91ac that runs great. I have learned that YS engines are thirsy beasts and always smoke, even when they may be on the lean side. Don't be concerned with the smoke, use a tach to set your needles. Fuel leaking from your carb when the engine is not running is (from what I understand) a sign of a malfuntioning regulator. This seems to be the most common problem with these engine so keep a spare reg diaphram handy. The diaphram is a thin silicone membrane and it is easily damaged.

Go to the YS forum and do some reading, there is lots of info there and I'll bet, all the answers you are looking for.

Enrique-F3A

[/b]What fuel are you using, how much nitro ?

mpalermo

Wildcat 20% heli, I added 5 oz castor to it.

Enrique-F3A

In spite of the instructions manual says that the engine can run on 15 % nitro, my personal experience with YS engines, is that most of them do not run properly if the nitro content is lower than 30 %. I have a 91 FZ that only runs on 30 % nitro. I have tried to use 20 % and got bad transition and bad idle. Castor oil is not recommended with YS engines, only pure synthetic !.

Also try this: Take out the main regulator screw and carefully check the inside parts of the regulator, plunger and spring. Take out the two body regulator screws, remove the body and carefully check the silicone diaphragm for integrity. Clean all parts and assembly the regulator. Do not over tight the two body regulator screws, adjust the main regulator screw to be flush with the body. To avoid backfiring use a time delay glow driver !

freakingfast

My Feedback: (3)

A lean run can spin a back plate or spin a prop. If this is what happened you could have thown the prop,double nuts or not. Keep everyone behind the prop arc. The 1 1/2 turns out is not set in stone but it's usualy a good starting piont. Try going richer. If I cant slow an engine down buy going rich something is wrong, stop. I don't see filters in your pics. Crud in the fuel system is the # 1 culprit causing problems on YS engines. This can easly happen when setting up a tank.

freakingfast

My Feedback: (3)

By the way, I've had well tightened "C" clamps unscrew by vibration. I saw the test stand start to go and I caught it at the last second by the fuel tank [sm=omg_smile.gif].
At least tie the "T" handle so it cant turn. I now use two lag screws to hold it down.

isaacslaw

My Feedback: (4)

I would have to say the engine is definitely lean. Be very careful with this engine and make sure you don't stand in the prop arc or in front of it It will shred aluminum spinners when it backfires and throw the prop savagely.

I would also say that castor oil in this engine might not be the best (don't flame me castor guys). I have a 110fz and had to spend quite a long while polishing my valve stems from the baked on castor oil it was causing all kinds of problems.

These engines are much much much different than two strokes. They are much different than other 4 strokes. You need to spend time to fully understand how they work and how they tune. Start with the regulator screw flush with the housing. Set your high speed needle at full throttle and make sure its a LITTLE bit rich. Then set your low needle at idle (remembering that the low needle is an air bleed and works the opposite of most two strokes turn in to richen, out to lean). If the RPMs rise at idle, richen it. If they lower at idle, lean it. Finally, set your regulator for good transition. If transition is sluggish, try leaning the regulator, but it could also need adjustment the other way. You may find that the regulator can only be set properly by observing what it does in the air.

With the YS 110, after every adjustment, you need to run the thottle up to full to sort of clear it out. You will not be able to tune it properly without doing this. Also, you must also check other things in the system fuel lines, fuel filters, tank pressure, etc. ALL of these things affect the tuning of the YS. Make sure all gaskets are set right and don't leak. Make sure all screws are tight but not too tight. YS requires patience to tune properly. Also, I do not know how many gallons of fuel are through it, but if it's new, you just need to run about 3 gallons through it before it finally settles down to its normal state.

THese are really tremedous engines, but take some time to figure out. THere is a thread called "YS Club" in the 3d forum where there is a lot of information from some very knowledgeable people. Also, the support forum for YS is really good. Good luck.

isaacslaw

My Feedback: (4)

OMG I am looking at the picture of your set up a little more carefully now and am not seeing a check valve. It looks like you also have a fuel line that is not hooked up to anything possibly a vent line open to the aptmosphere. This could be why you are lean. You must have a completely sealed fuel system. The check valve goes between the tank and the pressure nipple. The arrow needs to point towards the tank. You also need fuel filters in both of the lines. If your tank does not have enough pressure (or no pressure) the YS will always be lean.

Flyer95

My Feedback: (1)

Hello

Run the engine without the spinner backplate until the needles are set correctly. YS engines usually run great on 10% nitro but more is better for maximum top end performance.
It seems like your main needle is too rich? Have the glowbattery connected and if it can pass thru midrange and get to full speed then you know the main needle is too rich. If it stops even with the glowbattery connected then it can be lean or there is another problem.

nonstoprc

My Feedback: (90)

When you disconnect the vent line from the tank, does the tank de-pressurize? If not, something is wrong with pluming. It is important for the engine to receive pressurized fuel flow.

The screw on the regulator body can be adjusted. Screw it in to lean, and out to rich. Do it in 1/8 increment.

From your description, it seems the engine is lean in the middle because of fuel starvation. You could try to turn the regulator adjustment screw 1/8 turns out to see if the situation improves.

mpalermo

I took it apart and was just about to empty the fuel tank when I took that picture!!

I took the diaphram apart last night and put a fuel fiter in line, I cannot believe I overlooked that, see if I have better luck today.

@nonstoprc

Yes the tank is pressurized, when the engine quits it seems to push fuel through the plumbing and right out the carb.

Is that normal? do you need to depressureize each flight?

rcdude7

My Feedback: (264)

It is not normal for the fuel to leak out through the carb. I depressurize only to refuel, or defuel the tank.

nonstoprc

My Feedback: (90)

Yes. fuel is pressured all the time. I de-pressurize after each flight to avoid fuel being pushed to the carb/engine. also a good idea to do so at the end of the day.

Is the screw on the regulator body set flat with the body itself? That is usually the recommended setting. Try to screw it out 1/4 turn. The screw controls the amount of fuel being delivered to the carb. I bet it was not enough in your early run.

Iflyglow

My Feedback: (79)

You need to really go to the YS forums. First off, you need to get rid of the fuel with castor in it. It is intended to be run on 20/20 Synthetic only. Otherwise you will carbon a valve stem, and stick the valve (Really bad things happen then).[] A YS is not the only engine out there that will spit the prop amd destroy the spinner.[)]
Any of the normal YS's non-DZ versions will run just perfect on 20/20. You do not in any means need 30% to make a .91AC - 1.40S run good.
The 20/20 thing is the reason that Wildcat, power master, Cool Power Pro Pattern, and so on market fuel for YS's with straight synthetic oil.

Clip straight from Wild cats site

2 & 4 Cycle Available in 10%, 15%, and 20% nitro blends, 2 & 4-CYCLE fuels were developed with 4-stroke engine performance and protection in mind. Wildcat 2 & 4 cycle fuels contain 18% oil volume (except for the YS/20 which contains 20% total oil) and is totally synthetic.
As a side note WILDCAT's YS/20 fuel actually contains 20% oil content, some manufacturers do not actually use 20% oil, check with the manufacturer to be sure. Because of the 18% oil content, WILDCAT 2 & 4-CYCLE fuels can be run in any 2-stroke engine (except ducted fans) where a fuel with total synthetic oil is desired.

http://www.powermasterfuels.com/products/Pattern.html

Enrique-F3A

Mpalermo: If you can not make the engine to run properly after trying all the hints you have received here, try 30% nitro as I posted before. Once again, not all the YS engines run fine with less than 30 % nitro.

Iflyglow

My Feedback: (79)

mpalermo,
I am willing to bet that it is a setup error or lack of YS tuning experience and not the fact that 30% is better than 20%. First off you need filters, and check valve installed correctly, then you need at least the correct fuel to start with 20/20.

Enrique-F3A

.

Iflyglow

My Feedback: (79)

First off, make sure you either have an OS f or YS plug. Second step, make sure you are running either a 14-10,15-8, or 16-6 prop. Third step, double check all of your plumbing, and filter installations. Fourth step, amke sure you have the correct fuel.
These are all steps that if not followed will not allow amyone to help to figure out what is wrong.
If you continue to have problems, Talk to Troy Newman in the YS forums.[)]

Checking out these web pages maybe very helpfull.

http://tech.flygsw.org/ys_editors_notes.htm

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

mpalermo

First off SUCCESS.

I took all your suggestions and ran through a half a gallon today with 0 problems!!!

I have no idea which one fixed it but I consider it broken in enough to get in a plane to start flying!!!

Again THANKS!!!

Iflyglow

My Feedback: (79)

Mpalermo,
I would highly recommend that you switch to all synthetic oil though. The carbon will from that much castor will raise hell with both the valves stems and gumming up the regulator. Otherwise it sounds like to have it figured out.