X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao104.cox.net ([68.230.241.42] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2629655 for flyrotary@lancaironline.net; Thu, 03 Jan 2008 14:17:58 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.42; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao104.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20080103191717.URPX18222.fed1rmmtao104.cox.net@fed1rmimpo02.cox.net> for ; Thu, 3 Jan 2008 14:17:17 -0500 Received: from BigAl ([72.192.143.193]) by fed1rmimpo02.cox.net with bizsmtp id YjHN1Y0064AaN600000000; Thu, 03 Jan 2008 14:17:22 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: Weak Spark Date: Thu, 3 Jan 2008 11:18:34 -0800 Message-ID: <000001c84e3d$6f2de730$6401a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C84DFA.610AA730" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C84DFA.610AA730 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =20 =20 All this talk of weak spark got me thinking again about my 20B. It has = the stock CAS. I have found that the spark is weak and sometimes = intermittent when cranking. When I noted this, I was sure something was wrong. I = then checked using the Mode 8, and the spark was great. It would start and = run, so I forgot about it. The engine always started and runs fine, but I = have noticed more recently on cold mornings (meaning about 40F here in SoCal) that the starting was a little more hesitant, and would fire = intermittently for a bit before getting going. =20 I recall when we were checking timing on the dyno, it would not fire the timing light consistently =96 figured it was the light. On recent = flights, on two occasions, after steady cruise for =BD hour or so; there was a very = short duration power sag; just a second or two and then back to normal. No roughness; just some power loss that gets your attention, and then = it=92s OK. I=92m burning unleaded mogas, so shouldn=92t be the famous S.A.G. others = have experienced. I have no explanation. =20 These things, taken together, make me wonder if I=92m really getting the strong spark I should be getting. I know that during cranking it is = barely enough to fire the plugs. I haven=92t checked it when running cuz = it=92s a little difficult to hold a wire off and see how far the spark will jump = when that prop is going right there. But I guess I need to make a check of = that. =20 What sort of cranking spark should be expected? Other ideas on what to check? Is it something about the EC2 and the CAS? =20 Al =20 =20 =20 =20 =20 Subject: [FlyRotary] flooding =20 I made it out to the airport today, soldered up the CAS and installed = it. Before I cranked it over, I put it in mode 8 and fired it off. The = usual nice blue sparks. Then set it to mode 0 and cranked with the plugs out = and pumps/inj off. No spark. Cranked and looked again. Every so often = there would be a weak spark or 3, but most of the time, nothing. So little or = no spark ------=_NextPart_000_0001_01C84DFA.610AA730 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

All this talk of weak spark got me thinking again = about my 20B. It has the stock CAS. I have found that the spark is weak and = sometimes intermittent when cranking. =A0When I noted this, I was sure something was wrong.=A0 = I then checked using the Mode 8, and the spark was great. It would start and = run, so I forgot about it. The engine always started and runs fine, but I have = noticed more recently on cold mornings (meaning about 40F here in SoCal) that = the starting was a little more hesitant, and would fire intermittently for a = bit before getting going.

I recall when we were checking timing on the dyno, = it would not fire the timing light consistently – figured it was the = light.=A0 On recent flights, on two occasions, after steady cruise for =BD hour or = so; there was a very short duration power sag; just a second or two and then back = to normal.=A0 No roughness; just some power loss that gets your attention, = and then it’s OK.=A0 I’m burning unleaded mogas, so shouldn’t = be the famous S.A.G. others have experienced.=A0 I have no = explanation.

These things, taken together, make me wonder if = I’m really getting the strong spark I should be getting.=A0 I know that = during cranking it is barely enough to fire the plugs.=A0 I haven’t = checked it when running cuz it’s a little difficult to hold a wire off and = see how far the spark will jump when that prop is going right there. =A0But I = guess I need to make a check of that.

What sort of cranking spark should be expected? = Other ideas on what to check? Is it something about the EC2 and the = CAS?

Al

Subject: [FlyRotary] flooding

I made it out to the = airport today, soldered up the CAS and installed it. Before I cranked it over, I = put it in mode 8 and fired it off. The usual nice blue sparks. Then = set it to mode 0 and cranked with the plugs out and pumps/inj off. No spark. Cranked and looked again. Every so often there would = be a weak spark or 3, but most of the time, nothing. So little or no = spark

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