Hobbsy

My Feedback: (102)

Kostas, you need to set the LowSpeed needle at 1.5 turns out from closed to begin. My guess is that your engine is smoking a lot before it quits, is this true, if true there can only be two things wrong. Either the regulator is not lean enough or defective or the HighSpeed needle is too rich. 2 1/8 turns is a long way out.

Hobbsy

My Feedback: (102)

Kostas, you need to set the LowSpeed needle at 1.5 turns out from closed to begin. My guess is that your engine is smoking a lot before it quits, is this true, if true there can only be two things wrong. Either the regulator is not lean enough or defective or the HighSpeed needle is too rich. 2 1/8 turns is a long way out.

Hobbsy

My Feedback: (102)

Kostas, you need to set the LowSpeed needle at 1.5 turns out from closed to begin. My guess is that your engine is smoking a lot before it quits, is this true, if true there can only be two things wrong. Either the regulator is not lean enough or defective or the HighSpeed needle is too rich. 2 1/8 turns is a long way out.

Hobbsy

My Feedback: (102)

Kostas, you need to set the LowSpeed needle at 1.5 turns out from closed to begin. My guess is that your engine is smoking a lot before it quits, is this true, if true there can only be two things wrong. Either the regulator is not lean enough or defective or the HighSpeed needle is too rich. 2 1/8 turns is a long way out.

Kostas1

[8D]Mmmm,i haven't noticed anything like this.
But tomorrow i plan to test run my engine again.
So i will see that?
Also you think that 2-1/8 is a lot?
What then should i do?
Should i lean it,but how much?
Also this is the problem,you think?

lennyk

My Feedback: (12)

this sounds like a regulator problem, you may want to take down the regulator and check if there is
some kind of blockage in the little holes in the housing.

Kostas1

Regulator is in the diaphragm?
Sorry but i don't know anything for YS engines.The YS 53 FZ is my first,and i will think very much to buy another one.

Kostas1

Hi members.
I tested my engine again with the high speed 1,5 out and low 1,75 out but nothing.
The engine works very good on idle but when i am going from idle to full throtle the engine stops.
Also if the engine stays for some time[seconds to minute] at idle,when i am going to full throttle the engines rpm increases very very very slow.
What is it happening?

Hobbsy

My Feedback: (102)

If it is smoking and missing while doing this, the regulator is too rich, turn it clockwise 1/8th turn and try it again.

Kostas1

You ask if i see smoke when the engines stops?
No this is not happening.

DarZeelon

Kostas,


Is your fuel tank sealed and pressurized by the front-left nipple of the engine (on the same side as the carburettor feed nipple), through the one-way check valve (the tank should be strong enough to hold about 5 psi (0.33 bar), without bursting, or leaking. A Hayes tank is very good for this)?

This engine uses suction for fuel feed, only during idling.

At RPM higher than 2,000 pressurized fuel is a necessity, not only a 'nice to have' option.
The fuel system absolutely relies on this.

This engine's 'mechanical fuel injection' system relies on high pressure fuel feed, but it does not have a real 'fuel pump'; just an air pump, to pressurize the fuel tank and a regulator to control the fuel dosage.

Also, does the one-way check valve work correctly? It must only allow flow from the engine to the fuel tank and not vice-versa.

Make sure you have not crossed the fuel lines and nipples, using the drawing in the manual.

Kostas1

Hi again.
Em,my tank is 12oz Dubro and the check valve works perfectly.
But my fuel lines are not straight,crossed.Do you think that this can be the problem?

DarZeelon

Kostas,


What I meant is that you should check if any nipple is connected to the wrong tank outlet... Crossed up; not crossed over...

If something is connected incorrectly, or pressure is not retained in the tank, it will not work at all.

Kostas1

�ο,all lines are in the correct position and the engine is running well on idle.
Also i don't have any pressure leaking from somewhere.
But when i advance to full throttle my engines rpm are decreasing unexpectadly.

DarZeelon

Kostas,


This means either one of the following:

1. The engine is not pressurizing the fuel tank (either the engine isn't supplying pressure, or the one-way valve isn't working, or you have an obstruction in the mechanism).

2. The high-speed needle is too closed.

3. The mid-range is too lean (regulator pressure too low).

4. An obstruction in the fuel passages.


There is no other apparent reason.

Kostas1

Îœy YS is pressurizing the tank because when i disconnect the fuel line from the check valve pressurized air gets out of it.
So in this case is there any possibility of a check valve problem?
Also can you explain me the 3rd reason you said?
Regulator is in the diaphragm,correct?

DarZeelon

Kostas,


If the regulator is malfunctioning, it will put out too low a pressure, so the engine will not receive enough fuel for part throttle operation, and/or not enough to increase its speed.

The behavior is like a normal engine, with the low-speed needle set too lean.
The engine may idle very nicely, but when a greater need for fuel arises, the engine will cut out and die.

The diaphragm could be perforated, or there could a blockage in a fuel/air passage, within the regulator housing.

Kostas1

So i will replace my check valve and also if there is a blockage in a passage?

DarZeelon

Kostas,


Don't replace your check valve yet, since you wrote the tank remains pressurized, it may be OK.

Check the regulator diaphragm and clean out the regulator mechanism, with compressed air, or with a silicone compatible solvent; not with a carburettor cleaner, nor with WD-40.

Kostas1

please give me some time to try it,and test again my engine.

softlanding

My Feedback: (246)

did YS make a FZ 53 engine model that did not have a low speed needle on the carb?

Hobbsy

My Feedback: (102)

Yes they did, I owned one for a few years. the upgrade kit was $35.00, Dave Shadel the YS factory rep at the time told me it would be a waste of 35 bucks to do the upgrade. They worked very well without it. The airbleed trim, (low speed needle) has very little authority anyway.

Jesse Open

softlanding

My Feedback: (246)

Thanks for the info Jesse, I bought a plane with one on it that looks almost new, and the other engines I googled all had a low needle, When I hook up the fuel tank so I use the diagram for the newer engine?

Jerry