YS 140L tuning questions

[jim ivey]

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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