X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 15 Jan 2006 23:53:48 -0500 Message-ID: X-Original-Return-Path: Received: from wbm1.pair.net ([209.68.3.41] verified) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 927451 for lml@lancaironline.net; Sun, 15 Jan 2006 12:18:07 -0500 Received-SPF: none receiver=logan.com; client-ip=209.68.3.41; envelope-from=adam@validationpartners.com Received: by wbm1.pair.net (Postfix, from userid 65534) id 9BBF526CA4; Sun, 15 Jan 2006 12:17:13 -0500 (EST) Received: from 69.117.213.55 ([69.117.213.55]) (SquirrelMail authenticated user adam@validationpartners.com) by webmail1.pair.com with HTTP; Sun, 15 Jan 2006 12:17:13 -0500 (EST) X-Original-Message-ID: <1144.69.117.213.55.1137345433.squirrel@webmail1.pair.com> X-Original-Date: Sun, 15 Jan 2006 12:17:13 -0500 (EST) Subject: Unexplained engine vibration From: adam@validationpartners.com X-Original-To: lml@lancaironline.net User-Agent: SquirrelMail/1.4.5 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal My brother had a similar experience in his Extra 300. It turned out that the throttle cable making contact with the cowl. Any part that is rigidly attached to the engine will tranmit vibration to the airframe. In his case, the problem would come and go depending on power settings and flight regimes. At high power, the engine would torque on its mounts, bringing the cable in light contact with cowl. That was all it took to transmit lots of noise and vibration to the airframe. Look for any rub marks inside the cowl, especially around the baffling. Trim as needed to provide clearance. The engine can move quite a bit, so have at least 1" clearance. -Adam Molny