[NSRCA-discussion] OS 140RX rough and inconsistent idle

[Scott Smith]

More thoughts on the bearings....

Those generic bearings that performed so well for me at the beginning of the
season lasted 50 flights.  Front bearing developed some axial play
(crankshaft moves in/out ever so slightly.)  Idle and transition has become
inconsistent the last few flights so I'm waiting on a Tower order to come
in.

http://www.toolpartsdirect.com/cgi-bin/grouplisting.cgi/bearings/makita is
out of stock on the rear bearing until 7/17...guess we cleaned them out!
(Only out of stock bearing in the entire list, kind of funny.)
  -----Original Message-----
  From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Rick Wallace
  Sent: Monday, June 26, 2006 9:13 PM
  To: nsrca-discussion at lists.nsrca.org
  Subject: Re: [NSRCA-discussion] OS 140RX rough and inconsistent idle


  Ed -

  two thoughts on bearings -

  1. I've heard from others that a worn front bearing can be the cause of
idle problems - has that one been changed lately?

  2. rear bearings - I've not had real success w/ any bearing other than an
OS EFI bearing installed just as it comes out of the bag - don't know how
long they last because both engines are on their second or third season on
the same rear bearing... Stock bearing, aftermarket stainless, Boca's of
various flavors all had finite - and short- lives in my engines ...

  It'll be great to see you on the flight line in Muncie!

  Rick




----------------------------------------------------------------------------
    From: "Ed Miller" <edbon85 at charter.net>
    Reply-To: NSRCA Mailing List <nsrca-discussion at lists.nsrca.org>
    To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
    Subject: Re: [NSRCA-discussion] OS 140RX rough and inconsistent idle
    Date: Mon, 26 Jun 2006 13:56:41 -0400


    Thanks, looked at that so far when I removed engine, all looks normal.
Taking the engine apart in an hour or so.
    Yes, I'll be getting fuel from Scott Thursday.  I figured this was
better than cramping you guys on the trip out to Muncie.  I'll call you
tonight.
    Ed.
      ----- Original Message -----
      From: DaveL322 at comcast.net
      To: NSRCA Mailing List
      Sent: Monday, June 26, 2006 1:39 PM
      Subject: Re: [NSRCA-discussion] OS 140RX rough and inconsistent idle


      Ed,

      Long shot - but double check throttle servo mount/linkage, and
mounting of engine, softmount, nosering, pipe, etc - any of that stuff gets
loose, funny things can happen.

      Anderson should have fuel for you.

      Dave

        -------------- Original message --------------
        From: "Ed Miller" <edbon85 at charter.net>

        > Have an OS 140RX that has developed a rough and inconsistent idle.
Engine
        > runs perfectly except for idle. It has a Mintor head with either
an OS F or
        > K&B 1L in center plug and an OS A5 in the angled plug position, a
Perf Spec
        > AAC piston/liner assembly and a Boca sealed SS rear bearing. I
have the head
        > mounted with angled plug towards the front or carb side of engine.
Fuel is
        > S&W 20 nitro, 16 synthetic and 2 castor. Engine has 7 gallons of
fuel run
        > through it. Prop is an APC 15.75 x 11 3 blade by Dave Lockhart.
The lowest
        > I can get the idle before it quits is 1900 ~ 2000 rpm and it is
rough,
        > sounds like it is firing every other revolution. Idle mixture
screw is
        > working, I can richen idle to poi! nt wher e engine will barely
transition from
        > being rich and I can lean mixture so the transition is fine but
engine slows
        > at idle like it is too rich. While it is slowing with either the
idle
        > mixture screw lean or rich, engine is rough, again like it often
fires every
        > other revolution at times. I used to be able to reliably idle this
engine at
        > 1300 rpm. I have a second OS 140RX set up exactly the same except
it doesn't
        > have the AAC piston/liner and it runs/idles perfectly. Tried
cleaning the
        > carb/spray bar with no change. I once had a Super Tiger that
exhibited
        > similar characteristics due to a worn out con rod. Is it possible
the con
        > rod on this OS could cause this issue ?? Any suggestions will be
greatly
        > appreciated.
        > Ed M.
        > _______________________________________________
        > NSRCA-discussion mailing list
        > NSRCA-discussion at lists.nsrca.org
        > http://lists.nsrc! a.org/m ailman/listinfo/nsrca-discussion


--------------------------------------------------------------------------


      _______________________________________________
      NSRCA-discussion mailing list
      NSRCA-discussion at lists.nsrca.org
      http://lists.nsrca.org/mailman/listinfo/nsrca-discussion


    >_______________________________________________
    >NSRCA-discussion mailing list
    >NSRCA-discussion at lists.nsrca.org
    >http://lists.nsrca.org/mailman/listinfo/nsrca-discussion


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20060627/23d44000/attachment.html