Mailing List flyrotary@lancaironline.net Message #43255
From: Mark Steitle <msteitle@gmail.com>
Subject: Re: [FlyRotary] The SAGA continues; More checking basics and development progress
Date: Fri, 20 Jun 2008 21:06:01 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Chris,

As you've probably read from the archives surging is usually caused by an overly lean air-fuel ratio.  What is your A/F reading during the surging? 

Mark S.

On Fri, Jun 20, 2008 at 8:41 PM, Christopher Barber <CBarber@texasattorney.net> wrote:
Well, to continue the saga, I have not run the new 13b much since I got it running a few weeks ago due to the EM2 not showing oil pressure as it should.  It was giving me erratic readings like -1, -3 etc.  I hand propped the engine before I ran it and oil pumped through the system fine....much onto the hangar floor...alas, the sacrifices for certainty ;-).  Also, during my short runs everything heated up in the oil system evenly and the oil temp stayed pretty much in line with coolant temp.  BUT, since I was not sure if this was a gage/sender issue or an actual oil system problem I was very cautious about my few short engine runs.
 
Well, today while dreading the idea of dropping my pan, I happened across an extra oil pressure sender (still in the package) I happened to have.  I had seen it laying around for a while, but didn't give it much thought until I was thinking about dropping the pan. Low and behold, The problem was the sender.  I am getting good pressure reading now, along with coolant and oil temp. Yeah.  I am surprised at the temps as they seem to be staying in check considering the 95 + degree Houston weather.
 
I am able to start the engine, shut it down and restart it (something I was not able to do with the old engine).  It is somewhat difficult, but seems to be getting easier as I continue to tweak things (ie timing).  I am trying to do the various tuning via Tracy's manual.  To be honest a  lot of the information in the manual is seemingly abstract until I actually get to the step and/or problem.  So, tonight, I got it to run, and it seems to run better, but......
 
I am having a surging problem.  It seems intermittent, but it just may be I have not been setting the throttle quite the same way as I get use to it all.  Also, I have had the coil C/B pop on me several times now....it seems as if this is when the engine is near or at idle.  I have not had a chance to look into this as of yet.  Also, I have gotten a number of horrendously loud/powerful backfires.  Not sure what changes as the engine may have run fine.  It backfires when attempting to start.  I wait a few minutes and it may then start.  Gee, isn't inconsistent crap fun <g>
 
I just did a search of the archives on the surging issue, but have just started reading the 105 post on the topic.  Seems our own Mr. Slade had the same problem back in the day <g>.
 
Well, it is the middle of my work week and I gotta turn in soon, but I wanted to share that it seems as if actual progress is being made (hmmmm, wonder what will screw this positive statement up<g>) as the Saga continues.
 
All the best,
 
Chris

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