YS dies at bottom of stall turn - Help!!

Mon Jun 28 12:54:09 AKDT 2004

I had exactly the same problem the first time that I flew at the district championships in Florence KY. To compensate for my planes desire to roll off of their paved runway I reduced the idle. Flight after flight I would land deadstick, and always at the bottom of the double stall turn in the intermediate pattern. I became increasingly frustrated because it would run in every attitude on the ground. Nose up, nose down, and wouldn't even think about quitting.

Bottom line, you guessed it, the idle was set too low. After four wasted rounds and changing check valves, idle mixtures, glow plugs, etc. It was something so simple. Why it always stopped at the bottom of a stall turn was beyond me. Try returning the engine to factory settings and kicking up the idle a little bit, and you will be fine.

"Atwood, Mark" <atwoodm at paragon-inc.com> wrote:
I'm putting money on the Glow plug. I had almost this same problem and symptoms with a DZ...starting getting rich and dying on long idles....new plug...and I had a brand new motor.

good luck..

-M

-----Original Message-----
From: discussion-request at nsrca.org
[mailto:discussion-request at nsrca.org]On Behalf Of Eddie Batchelor
Sent: Monday, June 28, 2004 1:07 PM
To: discussion at nsrca.org
Subject: RE: YS dies at bottom of stall turn - Help!!

Thanks Troy & Dean.
I'm gonna try you're suggestions and report back.
I realise you can't "tune" an engine on the internet, but the advice is
invaluable.

Troy. I adjusted the idle by turning the idle screw out to lean it. - what
you said makes sense and I'm gonna next go the other direction. I thought it
was rich because the motor seems to slow down to die.

The regulator is flush with the case - actually still in the factory
location. the only adjustment I've made to the regulator was to turn it in
1/2 turn, thinking maybe I was getting too much fuel. I since put it back
(decided it wasn't a regulator problem).

I'll try to describe how the motor is running. it never dies at idle on the
ground and transitions great to WOT (no hesitation at all). Pull it back
down to idle and it will possibly move around somewhat(400-500RPM) but I
can't identify an increase or decrease in idle, it just seems to move
around. NOW if I increase the speed by 1 click of the throttle stick (not
the trim)then the motor will struggle to run and possibly die. if it does
take the throttle it sags a little before catching up. Again I'm talking
about less than 1/4 throttle. From there on faster it runs great. I was
interpeting this to be rich on the low end.

I'll try richeneing the bottom ( turning the low speed needle in(clockwise)
and change the glowplug. I am still on the original glowplug.

BTW -this motor ran so good out of the box that I didn't touch anything up
until now.

thanks again and I'll let you know what I find out.
Eddie

-----Original Message-----
From: discussion-request at nsrca.org
[mailto:discussion-request at nsrca.org]On Behalf Of Eddie Batchelor
Sent: Monday, June 28, 2004 10:34 AM
To: discussion at nsrca.org
Subject: YS dies at bottom of stall turn - Help!!

Facts: YS110 powermaster 30% Heli fuel Ys glowplug APC 15X10 turning 8800
and idles between 1800-2000.
Problem:
My fairly new YS110 (about 2 gallons of fuel thru it) has started dieing at
the end of prolonged downlines -such as coming out of a stall turn or on
final approach.

I have done the following so far:
1. assumed the idle was rich - leaned it out until the motor started
throwing the prop. Ok now it's too lean, so I richened it back up.

2. changed the tank and fuel lines.

3. discovered one of the in-line fuel filters partially unscrewed. tightened
this up

4. changed the throttle servo that appeared to have deadband around the idle
area(apparent bad pot)

I've attempted to fly after each of these changes and the motor will die
when I add throttle at the bottom of the stall turn. Now if I give a little
throttle during the downline & not let the motor slow down completely it
appears to do fine.

I want to be able to do a stall turn or a big loop and let the plane pull
out at the bottom with the motor idling and continue flying (at idle) until
I wish to add power.

Another example is on a landing approach when you realise you're a little
short and try to add just a blip of power to reach the runway, it dies about
then. (has twice now)

Does anyone see a "glaring" mistake I'm making, or have a suggestion of what
next to look at. I realise I'm at the bottom of the learning curve with YS
4-c motors and it ain't no fun :-))

Any help will be greatly appreciated.

Eddie

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