Hi there.
I have a YS 53FZ and also a great problem when running!!!From idle when i go to full throtle the engine stays on a very low rpm and slowly shuts off!???I checked for leaking pressure,wrong connections and diaphragm position!Also when i puss the diaphragm the rpm changes!
What is going wrong?
Does anyone knows sth?
I uploaded the photo of my engine,installed in a Greatplanes Extra.

What percent nitro fuel are you using?

Has this engine run well in the past?

Are you SURE the checkvalve is on the correct line and it is connected to the correct fitting on the engine?

Also in this picture you can see that this tube when i am going to start my engine by hand,fuel will not pass![]

Your engine is running lean.

Could be your needle valve setting

Could be regulator problem

You could have the fuel lines connected wrong?

E,i run it with 10% nitro and 18% oil.
Also the engine is not mine.I bought it from a guy that told me that is running perfectly.
The engine when i first bought it was very clean inside,not any damage or damage on crancase.
And the check valve is in the correct position![&o]

There is your first problem. The YS 53 is a nitro hog. You need 20% nitro or higher to get reliable performance out of it.

Yea but i bought a fuel called Jet,to see how it works!I think it is good.Do you know it?Also what about Byron fuel?That contains 15% nitro and 20% oil.?Also do you have any pics of your YS engines?

Kostas,


...Only 20% nitro, or more is needed.

Also, as little as possible Castor oil, but no less than 20% total oil.

This engine will likely overheat with 15% nitro, or with less oil.


A 30% heli fuel mix is even better.


This goes for ALL YS engines, not only the .53FZ.
Only the 1.40 Sport can do with only 15% nitro.


But you might also have another problem, from what you are describing.

I wish i knew the problem.[]Anyway i will buy tomorrow 25% nitro and 20% oil from byron fuel,to see what is going on.
What other problem maybe is?

Back in your first post you say that you are pushing on a diaphram, which diaphram are you talking about?

Ιt is located in the down side of the engine.
You don't know YS engines?

Kostas,


Do you mean you are closing the adjustment screw?

This screw should be very close to flush with the surrounding surface.

You should not be able to directly push it, or even to see it, or there is something missing (the adjuster screw...).

You can read the *.pdf manual [link=http://www.ysperformance.com/pdf%20manuals/FZ63.pdf]here[/link] (it is the older .63FZ, which is identical to its older brother, the .53FZ).

No,i am not pulling the direct diaphragm!
It has a screw after ir,isn't it?
But when i touch the screw the rpm of my engine changes!
Is this a problem?

Kostas, here is the setup on one of my .53s, the LS needle is 1.5 turns out from gently seated and the HS needle is slightly less than 1.75 turns out from closed.

Î¥ea thank's!
Also my name is Kostas!M,very useful pics!I will try my engine tomorrow,again!And i will tell you all again![8D]

Kostas, any luck fixing your YS problems?

Hi.
I just fixed the idle and the engine works perfectly.
But when i am going from idle to full throttle the rpm lowers and then it quits.
How can i fix this?

Might still be lean on the high end needle valve. How many turns out is it?

Hi again!
It is 2-1/8 turns from fully closed position.
IS this ok?

Here's the 63 manual if that will help?

http://www.ysperformance.com/pdf%20manuals/FZ63.pdf

Enjoy,

Jim

Look at the topic,RE[:@]!!!!
Topic is Problem with YS 53FZ NOT63FZ-S.

Kostas,


Both Jim and I are saying the .53FZ is identical, for all practical purposes, to the older .63FZ.

We are not talking about the YS.63FZ-S, which uses a different regulator and a one-piece cylinder (and has several other improvements). An older version of the .53FZ did not even have an idle needle, BTW, so we are not even mentioning it...

So the YS.63FZ manual is identical to the one for the newer YS.53FZ that you have, which cannot be accesses, or linked, since it was written before there was a usable Internet...


The other thing that can be done, is if someone that has your newer version of .53FZ, would be able to scan the manual and to send it to you by E-mail.

i HAVE THE manual,but this doe not fix the problem!

Kostas, you might show a little respect to the people who are trying to help you.

Kostas, you might show a little respect to the people who are trying to help you.