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

[Ed Miller]

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 


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