---------------------------------------------------------- Commander-List Digest Archive --- Total Messages Posted Fri 07/13/07: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:10 AM - Re: Engine Cough? (Matthew J. Hawkins) ________________________________ Message 1 _____________________________________ Time: 08:10:41 AM PST US From: "Matthew J. Hawkins" Subject: RE: Commander-List: Engine Cough? JB- Looks like you might have nailed it on this one! We found the carb heat li nkage maladjusted - we'll let you know if that solves the problem. Many thanks! Matt -----Original Message----- From: owner-commander-list-server@matronics.com [mailto:owner-commander-lis t-server@matronics.com] On Behalf Of yourtcfg@aol.com Sent: Tuesday, July 10, 2007 1:02 PM Subject: Re: Commander-List: Engine Cough? After checking the other suggestions, It is probably an adjustment to the pressure carb. Try this. While it is acting jacking up, manually lean the carb and see if it clears up. If it does, it is rich, if not, most likely lean. There are two adjustment on the carb. One for idle mix, the other for "off idle" It is probably the off -idle but both will need touched up. If you have a manual for the engine it will cover this procedure, if not let me know and I can walk you through it. One last thing, make certain th e carb heat is not on. Sometimes the linkage will allow the carb to pull i n hot air and with the temps rising it could just now be showing up. If th e engine has had a backfiring incident recently, if could have bent the lit tle carb heat butterfly doors in the carb heat box. I have seen several of these over the years and they too will let hot air into the carbs causing them to stumble . Conversely, an exhaust leak in the cowling can overheat the ambient air in there and trick the carb into thinking it is really hot outside and it will try to compensate by leaning. jb 360-903-6901 pressure carburetors -----Original Message----- From: Matthew J. Hawkins Sent: Mon, 9 Jul 2007 9:07 am Subject: Commander-List: Engine Cough? l.edu> All- We're having a minor intermittent problem on the left engine of N2760B. Th ey are Lycoming G0-480-DIA's. Geared engine with pressure carburetors. When reducing power, the engine will cough/sputter as soon as it hit's 21" of manifold pressure. Doesn't quit - just skips and runs a bit rough. Doesn't happen when increasing power. All gauge reading in the green - nothing obvious. About 15 hours on the engines since major overhaul. Did not happen during first 10-12hrs - started during past couple of flights. Won't happen every time - but about 75% of the time. Just a little disconcerting on final! Any thoughts? Matt ******************** Matthew Hawkins Director, Marine Ops R/V HUGH R. SHARP 302-645-4341 FAX: 302-645-4006 hawkins@udel.edu ________________________________ ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message commander-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Commander-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/commander-list Browse Digests http://www.matronics.com/digest/commander-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.