Send the engine to:

YS Service
1295 Industrial Court
Gardnerville, NV 89410

I believe this is the only way to fix the problem.

Hello Dave, I ran the engine today and reseted everything as per instructions, it holds idle now but while at high or middle range the mixture richen (you can tell with the smoke difference), it actually ran almost ok in ground but doesn't hold in flight and shuts off below 1/4 throttle, should I send the engine anyway?

YES.

Hi Dave,
I've had many YS engines (at least 10) and all run great !
Except for this new YS 91 FZ.
(Bought two from Central around January)
Have tried everything in the book !
Idles ok in the ground (around 2000 and steady).
Top end is superb (9000 with 15X8), transitions smoothly,
Wildcat 20/20 - F plug.
BUT after a full flight, it just dies when I throttle back
for landing, even if I try not to idle under 2500.

Any suggestions ?
Happy flying
George Brod

Please return it to us.

Dave,

I bought my YS .91FZ from Central Hobbies in February and mine does the same thing as georgbrod's. (I am the one who started the other thread). Maybe a bad batch??

Maybe a couple of bad parts snuck into a couple of engines. We have not had any serious issues with 91's, so this is probably no huge cause for alarm.
If your problem persists, we should have you send it in.

Sent you a PM. The engine is on its way.

Dave -
Just bought a Goldberg Extra 300 that came with a fairly new YS 91.
My question is this.
I am not familiar with your engines yet and and am very confused as to how to route the fuel lines.
I have 3 lines coming out of the tank. 2 have 'Ts' since the plane has a cowling.
I would assume one is for refueling and one is a vent?
Do you have a manual that would show how the lines are routed? I am positive that the way they are setup right now is wrong. I can emial you a couple of pics if I could get your address.
At the front of the engine behind the prop adapter are 2 nipples on the top and one to the right slightly behind the 2.
Then, I have a nipple which I believe should be the inlet to the carb.
Can you tell me how to route these lines correctly?

Try www.ysperformance.com. The diagrams are there.

actually, if you try the website you gave me with the period at the end, you get an interesting message. Try getting there directly off what you gave me...

Interesting. I'll leave the period off in the future. Did you get the info you needed?

Yes. Thanks.
Does the engine pressurize the fuel tank which in turn feeds fuel to the carb, or does the pump feed directly to the carb?

The tank pressurizes from timed crankcase pressure and the REGULATOR adjusts the amount of fuel admitted to the engine at the various throttle settings. The regulator is not a pump.

Dave -
Understand. Thanks.

I am new to YS and have just got a new 110 15x8 os type F plug all in znlines synergy 90 3D go the engine from them too. Oh 25% cool power fuel.

i set up the engine on the ground not adjusting the regulator, and got a nice idle and hs setting but was quite rich to run the engine in. After runing 3 14oz tanks and getting used to the engine (etc). i flew the model but on landing and powering up to go around the engine heisitated but did pick up, on the second time around it died on the power up.

is it the regulator or low speed valve??

Hello,
I am to select the tune muffler for my YS170DZ CDI for AxiomeGP F3A Model:
I am considering 2 options:

> Hatori 821 (length is 235mm)
> Hatori 725 (length is 165mm)

what is your recomandation?

Amram Leshed
F3A Israel

Sorry guy but this forum is no longer supported by YS directly and hasn't been for some time now. The questions are usually answered by long time YS users now, not a rep from YS here in the USA.

E-mail is not a reliable way to get answers from YS here in the USA, usually a phone call is necessary.

I'd suggest you start a new thread and perhaps you'll get an answer from one of the other users, or perhaps you can contact a vendor who will ship to you?

Zeeb,

Not entirely true. Myself and Pete Cosky are in constant contact with Richard at YS and he has asked us to monitor and respond to questions for him. While not technically employed by YS, I speak to Richard regularly and have done quite a bit of testing on the new DZ engines. Pete Cosky is a longtime YS user how knows the older engines as well as anyone and between the two of us with the blessing of Richard and Richard answering any questions we can't answer, we do our best to constantly monitor this forum,

Archie Stafford

And I'll add a big thanks to the YS users who give a helping hand to get questions answered. We all jumped in to help when there was no one monitoring the forum just to be able to help others. There are a lot who love the YS engines and are happy to help in any way they can which is always welcome here.

Pete Cosky

Ah, didn't know that but it's been some time since I talked with Richard since I mostly fly GS gassers now but still have a couple of YS's floating around in the hangar....

I thought when Troy gave it up we were kind of on our own and while I've seen both you guys post with great tips/tricks, I didn't know Richard had asked you to keep an eye on the forum.

Good job guys and thanks for your efforts! [sm=thumbup.gif]

No reason why you can't still help out too. We all have not seen everything so the more eyes on an issue the better.

I have an old YS 120 vFZ that I bought new in 1995.
It has run great for many years.
It recently blew the con rod right below the wrist pin.
Richard overhauled the engine for me and I have run half gallon of fuel through it set very rich for break in.
I have a 16x8 prop on it, runs at 9100 peak and richened to 8800 rpm for flying.
(needle valve 1 1/2 to 1 5/8 open)
Using Wildcat 15% with 18% oil and several ounces of castor added to bring it up to 20%.
Has worked good for 15 yrs now.
The problem is the engine goes richer as the flight progresses.
When first started and warmed up a little, if I open full throttle, its very strong, 8800rpm.
iIf I bring it down to idle(2000RPM) it will idle fine, but when I throttle up its very rich.
Lots of smoke and maybe 7500 rpm.
I have set it according to Rick Matties instructions.
This was the first engine with an idle adjustment, its at 3 or more turns open, have tried many different settings.
It drops right down to 2000rpm and is steady at 3 turns open.

Thanks for any help,

Pete Stapleton

Pete,

Probably time for a ring at minimum and maybe bearings after 15 years. As the ring wears you will get more blow-by causing the crankcase pressure to go up which would aslo cause your mixture to go lean. BUT before we start there, lets cover the basics:

Regulator is clean?
New OD #F or YS #4 plug?
Valve lash set?

(Richard overhauled the engine for me and I have run half gallon of fuel through it set very rich for break in.)

The engine is going rich, not lean.
Seems to load up after running awhile.

Runs good when first started, I'm thinking a cold engine will run good on a richer mixture.
After I taxi to the runway and take off, its so rich it barely gets off the ground.
I usually just fly around at full throttle and it cleans up enough to fly, but it doesn't have the power it should.

As it comes up to operating temp, it;s probably then too rich.

I have cleaned the fuel system, but have not messed with regulator.
It's flush with the casing.
It has a fuel filter between the tank and the engine.
Glo plug is good, OS-F type.
Good pressure in the tank, will hold pressure for hours.

Explain the function of the regulator plug.
The instructions say it regulates the amount of fuel to the carb?
Should I turn it in to decrease the amount of fuel?

Thanks



Read more: http://www.rcuniverse.com/forum/m_10...#ixzz0tfImZM70