YS 140 FZ regulator question

[Tom Mitchell]

Hi Mike - Tom M. here.
Your high speed needle should be between 1-1/4 to 1-1/2 turns out,
maximum, before you mess with anything.  If you are not there, some-
thing is wrong.  Make sure the regulator is flush, and the low speed
needle is 1-1/2 turns out.  Eye balling is entirely adequate on the
 regulator.  The low speed needle valve is an air bleed.  You turn
it out to lean the idle.  Every time you change the low speed mixture,
you should expect to have to touch up the high speed needle valve.
When you have got it as good as you can with the high and low speed
needle valves, you should find that life is good except for the mid range
(i.e. transition).  Run the regulator in to lean the transition, and out to
richen it.  It doesn't take much to make it right.  We are talking 1/8
turns or less. I have never had to richen up the transition on a YS
4 stroke.
Tom

----- Original Message -----
From: <Legend5rc at aol.com>
To: <discussion at nsrca.org>
Sent: Monday, May 17, 2004 8:41 AM
Subject: YS 140 FZ regulator question


> Just finished a rebuild of my 140 FZ.  High end seems fine.  But the
engine slowly dies WITHOUT an rpm increase at low throttle leading me to
believe that the regulator is too rich.  With canopy off, I am able to pinch
the fuel line and then it will run for a short time before it gets that rpm
increase.  I did eyeball the regulator flush with the surface during
re-assembly, but I should have laid a strait edge across the surface to be
sure.  I have since turned in the regulator a half a turn and it is getting
better, but not as quickly as I would have expected.  My question is, if the
regulator was so far off to begin with, wouldn't the engine not have run at
all?  Is there something else wrong?  Don't want to damage the motor, but so
far everything seems OK and I will continue to turn that regulator in until
she runs right.  FYI, keep in mind I live at 5800 ft so my settings are
different from any low altitude folks.  Thanks.
>
> Mike Cohen
>


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