---------------------------------------------------------- Beech-List Digest Archive --- Total Messages Posted Mon 09/15/08: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:13 AM - Re: Bonanza with IO-520BB idles rough (Ian Dewhirst) 2. 08:08 AM - Re: Bonanza with IO-520BB idles rough (martymitchell) 3. 08:44 AM - Re: Bonanza with IO-520BB idles rough (Chuck) 4. 09:04 AM - Re: Bonanza with IO-520BB idles rough (martymitchell) 5. 10:52 PM - Re: Bonanza with IO-520BB idles rough (martymitchell) ________________________________ Message 1 _____________________________________ Time: 04:13:42 AM PST US From: "Ian Dewhirst" Subject: RE: Beech-List: Bonanza with IO-520BB idles rough I would look for an intake leak. -----Original Message----- From: owner-beech-list-server@matronics.com [mailto:owner-beech-list-server@matronics.com] On Behalf Of martymitchell Sent: September 14, 2008 1:16 PM Subject: Beech-List: Bonanza with IO-520BB idles rough --> I have an IO-520BB in my Beech Bonanza that runs rough at idle and low RPM. I have changed the spark plugs, cleaned the injectors, checked the mag timing (just installed after 500 hour inspection and new distributor block), and had a mechanic check the idle fuel pump pressure and idle mixture setting. I also did a compression check and all cylinders are above 60/80. There doesn't seem to be any difference in drop with each mag at various RPM's. I have not changed the ignition wires. Any ideas on other things to look for? Thanks! -------- Marty Mitchell Bonanza N44GN Read this topic online here: http://forums.matronics.com/viewtopic.php?p 4248#204248 ________________________________ Message 2 _____________________________________ Time: 08:08:23 AM PST US Subject: Beech-List: Re: Bonanza with IO-520BB idles rough From: "martymitchell" I have verified that all the hose clamps are tight and that all the intake bolts are secure, but not sure where else to look and how to determine if it's leaking. Thanks. -------- Marty Mitchell Bonanza N44GN Read this topic online here: http://forums.matronics.com/viewtopic.php?p 4377#204377 ________________________________ Message 3 _____________________________________ Time: 08:44:41 AM PST US From: "Chuck" Subject: Re: Beech-List: Bonanza with IO-520BB idles rough What is the largest difference between cylinder compression? You say all are at least 60/80 but how far apart are they and are they very different from the last time they were taken? When is the last time the prop governor was checked? Did it start being rough just after coming out of the shop for repairs? Could it be cam related? Bad lobe on cam? Best of luck. ________________________________ Message 4 _____________________________________ Time: 09:04:27 AM PST US Subject: Beech-List: Re: Bonanza with IO-520BB idles rough From: "martymitchell" Both mags were inspected, a new distributor block was installed on one due to a corroded terminal, and returned to the plane. I only did a brief compression check to see if anything really bad happened to a cylinder, but will have to go back and do it more carefully to get the exact numbers and will compare with existing numbers. Seems like the trouble began after the mags were pulled out and returned. I suppose it could be a bad cam lobe. The engine is 1500 hours TSO. The prop governor has not been checked for 1500 hours as far as I know. I'm planning to check the ignition wires today. -------- Marty Mitchell Bonanza N44GN Read this topic online here: http://forums.matronics.com/viewtopic.php?p 4385#204385 ________________________________ Message 5 _____________________________________ Time: 10:52:21 PM PST US Subject: Beech-List: Re: Bonanza with IO-520BB idles rough From: "martymitchell" Problem Found! I did a second compression check and took my time. Although all of the compressions are in the low to mid 60's, it appears that each cylinder has a valve leak, one exhaust and 5 intakes. I suppse that is why it idles so rough. Thank you all for your help and suggestions. I should have started off with a careful compression check. -------- Marty Mitchell Bonanza N44GN Read this topic online here: http://forums.matronics.com/viewtopic.php?p 4520#204520 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message beech-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Beech-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/beech-list Browse Digests http://www.matronics.com/digest/beech-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.