X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [204.127.198.39] (HELO rwcrmhc12.comcast.net) by logan.com (CommuniGate Pro SMTP 4.3.6) with ESMTP id 612846 for flyrotary@lancaironline.net; Sat, 23 Jul 2005 16:34:26 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.198.39; envelope-from=n3773@comcast.net Received: from rv8 (c-24-21-140-241.hsd1.or.comcast.net[24.21.140.241]) by comcast.net (rwcrmhc13) with SMTP id <2005072320334101500b931qe>; Sat, 23 Jul 2005 20:33:41 +0000 Message-ID: <003001c58fc5$cde73c60$f18c1518@rv8> Reply-To: "kevin lane" From: "kevin lane" To: "Rotary motors in aircraft" References: Subject: Lycoming debugging test - -HELP! Date: Sat, 23 Jul 2005 13:33:34 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01C58F8B.1F987B40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_002D_01C58F8B.1F987B40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I realize that this isn't exactly the right forum, but you guys seem to = have excellent debugging skills. my local RV group is totally worthless = ("I find the carnauba wax doesn't show fingerprints as much as = the....")(except Mike!) the on-field mechanics are sick of me coming = by. my O-320 RV-6A is having RAG (rpm attention getter) problems. it = runs fine until about 300' on take-off, then the rpm's drop to like 1700 = (from 2200). switching mags to electronic ignition(Rose) makes no = difference. mixture no diff. pulling the throttle it will seem to run = fine at 1700rpm. I have 4 new cyls that I am attempting to break in. = ground run ups can only go like 2 minutes before CHT's exceed 400 = degrees. I discovered I can get the rpm drop on the ground if I run it = a minute or so full power. cht's will typically approach 415 degrees = when the drop takes place. I don't know if the temp is significant or = not, it does seem that way. I have a brand new slick left mag. rose = checked the electronic ignition and could find nothing wrong, even put = it in an oven to test. I installed a new carb since the old one showed = signs of leakage (and I'm at whits end). no change. my fuel pressure = has been showing 8psi this last year, up from 6 psi when originally = installed.(no idea why) I installed a pressure regulator in-line which = works like a charm. I can dial whatever pressure I like. 2 psi makes = no difference. I bypassed the mechanical fuel pump and ran it just on = the facet electric. 2 psi, no difference. I discovered that you can run = the carb for maybe 30 secs with no fuel pressure while it burns off the = bowl gas. premier engines suggested induction leak making the engine run = lean. no leaks detected cold or hot engine. (pressurized intake with = vacuum, sprayed soapy water) if the engine didn't run right to start with then many explanations = would hold. but it runs fine for several minutes. it runs the same = under mag or electronic ignition both before and after the problem kicks = in. everyone really wants to blame the rose ignition, but I'm not = seeing any connection. with such a quick run-up my oil temp barely = registers, so I doubt parts are seizing. I have new mineral oil in it = for breakin right now. there is a bit of MMO in the fuel too I believe, = left over from a mechanics "what the hell" attempt from way back. my = cyls are all new, rebuilts, so no valve problems. I checked the push = rod lengths when I reinstalled them. the engine isn't missing when the = problems occurs, it simply won't run faster and it seems to prefer the = throttle pulled back to match the rpm it is putting out. I can't figure = out any more lean mixture scenarios to try. the new carb runs just like = the old one did. I recently replaced the mag harness with a much newer, = used one. I tested it and it was fine. the plugs are all new, but = again, no diff between mag and elec ignition. if I flip the ignition to = R and shut off the elect ig then the engine quits as would be expected, = no wiring problems. fuel, spark, air, timing, that's all there is. this damn lycoming = lawn mower has me stumped. my engine has been running fine up until = this (hey, we all have "cracked" cylinders, get out your microscope and = look!). you guys have any ideas? Kevin Lane Portland, OR e-mail-> n3773@comcast.net ----- Original ------=_NextPart_000_002D_01C58F8B.1F987B40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I realize that this isn't = exactly the=20 right forum, but you guys seem to have excellent debugging skills.  = my=20 local RV group is totally worthless ("I find the carnauba wax doesn't = show=20 fingerprints as much as the....")(except Mike!)  the on-field = mechanics are=20 sick of me coming by.
    my O-320 = RV-6A is=20 having RAG (rpm attention getter) problems.  it runs fine until = about 300'=20 on take-off, then the rpm's drop to like 1700 (from 2200).  = switching mags=20 to electronic ignition(Rose) makes no difference.  mixture no = diff. =20 pulling the throttle it will seem to run fine at 1700rpm.  I = have 4=20 new cyls that I am attempting to break in.  ground run ups can only = go like=20 2 minutes before CHT's exceed 400 degrees.  I discovered I can get = the rpm=20 drop on the ground if I run it a minute or so full power.  cht's = will=20 typically approach 415 degrees when the drop takes place.  I don't = know if=20 the temp is significant or not, it does seem that way.  I have a = brand new=20 slick left mag.  rose checked the electronic ignition and could = find=20 nothing wrong, even put it in an oven to test.  I installed a new = carb=20 since the old one showed signs of leakage (and I'm at whits end).  = no=20 change.  my fuel pressure has been showing 8psi this last year, up = from 6=20 psi when originally installed.(no idea why)  I installed a pressure = regulator in-line which works like a charm.  I can dial whatever = pressure I=20 like.  2 psi makes no difference.  I bypassed the mechanical = fuel pump=20 and ran it just on the facet electric.  2 psi, no = difference. I=20 discovered that you can run the carb for maybe 30 secs with no fuel = pressure=20 while it burns off the bowl gas. premier engines suggested induction = leak making=20 the engine run lean.  no leaks detected cold or hot engine. = (pressurized=20 intake with vacuum, sprayed soapy water)
    if the = engine didn't=20 run right to start with then many explanations would hold.  but it = runs=20 fine for several minutes.  it runs the same under mag or electronic = ignition both before and after the problem kicks in.  everyone = really wants=20 to blame the rose ignition, but I'm not seeing any connection.  = with such a=20 quick run-up my oil temp barely registers, so I doubt parts are = seizing.  I=20 have new mineral oil in it for breakin right now.  there is a bit = of MMO in=20 the fuel too I believe, left over from a mechanics "what the hell" = attempt from=20 way back.  my cyls are all new, rebuilts, so no valve = problems.  I=20 checked the push rod lengths when I reinstalled them.  the = engine=20 isn't missing when the problems occurs, it simply won't run faster and = it seems=20 to prefer the throttle pulled back to match the rpm it is putting = out.  I=20 can't figure out any more lean mixture scenarios to try.  the new = carb runs=20 just like the old one did.  I recently replaced the mag harness = with a much=20 newer, used one.  I tested it and it was fine.  the plugs are = all new,=20 but again, no diff between mag and elec ignition.  if I flip the = ignition=20 to R and shut off the elect ig then the engine quits as would be = expected, no=20 wiring problems.
    fuel, = spark, air,=20 timing, that's all there is.  this damn lycoming lawn mower has me=20 stumped.  my engine has been running fine up until this (hey, we = all have=20 "cracked" cylinders, get out your microscope and look!).  you guys = have any=20 ideas?
Kevin Lane  Portland, OR
e-mail-> n3773@comcast.net
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