YS 140L tuning questions

[David Harmon]

Those numbers are TT adapter nuts. The APC props have different hub
thickness depending on what size prop you are using. Some TT spinners
will not fully engage the backplate if the prop hub is too
thick....other TT spinners when tightened will distort the spinner
backplate.
You can add washer shims in front of the adapter nut to prevent the
distorting and shorten the adaptor nut if the spinner will not go on all
the way. It's kinda goofy but that seems to be the way it is. I asked a
few other flyers about this problem a few years back but they didn't
seem to know what I was talking about.
TT may make a short and long adaptor nut....but I couldn't find it on
their website.
 
Dave

-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]
On Behalf Of jim ivey
Sent: Sunday, June 01, 2003 8:00 PM
To: discussion
Subject: Re: YS 140L tuning questions


 lhncheol
You may have the wrong threaded adapter nut. Check that out. I'm not
familiar with 813A, or 814A. What are these numbers. Been a while since
I bought adapters.
 My 140l's run at full throttle about 1 1/4 to 1 1/3 needle opening.
That has a lot to do with nitro content. I run 30% heli fuel. I'm
guessing 2 turns out is a good starting place.
 
Jim Ivey

----- Original Message -----
From: Ihncheol Park
Sent: Sunday, June 01, 2003 10:19 PM
To: discussion at nsrca.org
Subject: RE: YS 140L tuning questions
 
Jim,
I just replaced the prop nuts with the standard YS washer and double
nuts, the problem of loosening of spinner and prop is gone.
 
It looks like the tru-turn adapter that I used worn out.  the large nut
is kind of loose on the shaft.
 
I never open the throttle fast because of what you explained (lean
condition).  I am also afraid to do so even with small YS 4-stroke
engines after hearing this engine broke two hyde mounts and damaged
airframe.  So, I opened very slowly, and little by little looking at the
muffler and the spinner, being ready to shut down.
 
Now, the high speed needle is about 2 and 3/4 turn out.  I went to full
throttle and stayed there about a minute and backed down.
 
The engine died slowly. (rich?)
 
I printed out Troy's explanation on how to set the engine and read it
over a few times.  Unfortunately, I don't have a plane ready for this
engine yet.
 
Each run of the engine didn't go more than 3 minutes to make sure the
engine doesn't get too hot on the ground.
 
By the way, do you people use Tru-Turn 813A for 140?  or 814A?  I used
814A because I already had it.  What's is the differences between the
two?
 
I know that without the spinner, 814A does not fit on YS 140L with very
long shaft.
 
Looks like I have to order both.
 
Thank you,
 
Ihncheol 

-----Original Message-----
From: discussion-request at nsrca.org
[mailto:discussion-request at nsrca.org]On Behalf Of jim ivey
Sent: Sunday, June 01, 2003 6:50 PM
To: discussion
Subject: Re: YS 140L tuning questions


lhncheol
When you open the throttle don't let it go wide open to the stops. This
will be a lean condition. Always adjust full throttle for barrel to be
straight up and down, not all the way open. This is really important
with a Hyde or similar mount that will stretch under full power.
 For the spinner use double prop nuts. One nut will lock the prop nut. I
also use washers to space the spinner so that the spinner bolt tightens
against the nut without bending the backplate.
 If you hear that loud hammering or pinging you are lean. That's why it
throws the props and spinner. Don't let it do that.
 The first tank on a rebuilt or new engine should be well on the rich
side. After that put in plane and fly, slowly leaning engine for a few
flights. The engines get more cooling in the air.
 There is a method to set the low end at 2000 rpm and to set max rpm. I
will let someone else talk about that.
 
Jim Ivey
 

----- Original Message -----
From: Ihncheol Park
Sent: Sunday, June 01, 2003 9:13 PM
To: NSRCA
Subject: YS 140L tuning questions
 
OK, finally, I got all the parts installed including the updates.
Here is the current setting.
Idle screw and 2 turn out.
High speed at 2 turn out.
Regulator screw 1/4 turn out from flush with case.
The engine is mounted upright on a stand with AAP muffler
Magnum #2, APC 15x12W.  (I listened to Troy Newman and bought the
props!!)

I had to use music wire support from mount to the muffler because it
kept
come loose within a minute of running.

At idle, the engine spits fuel out of carb a lot as in rich condition.
Going fine up to 2/3 throttle.
When near the full throttle, there is a sharp "Ping~" sound.  Spinner
and
prop got loose (tru-turn nuts are still on the shaft).  Fortunately, the
spinner cone was not damaged for the last 5 attempt.  (the cone came
loose
twice flying upto 15 feet).

Am I still lean?
Compression is very strong even with 3 head gaskets. Before running,
there
was almost no compression and had a little of hard time starting with
chicken stick.  (Excellent excercise on my right arm.  I could not use
kavan
starter because of very sticky soft cone staying on the spinner.).

Now, I am afraid if I will damage the engine.
What is a good way to keep the spinner and prop not to come loose?

Any suggestions?

Thank you,

Ihncheol Park




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