---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Wed 05/08/19: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:29 AM - Re: 277 keeps falling off the pipe (Richard Pike) 2. 11:39 AM - Re: 277 keeps falling off the pipe (George Alexander) 3. 04:27 PM - Re: Re: 277 keeps falling off the pipe (Stuart Harner) ________________________________ Message 1 _____________________________________ Time: 10:29:30 AM PST US Subject: Kolb-List: Re: 277 keeps falling off the pipe From: "Richard Pike" IT WORKS! Over the last couple of weeks we tried taking 2" off the prop length; no improvement. But a 60" prop is still plenty of prop for a 277, so no real harm done. We were about ready to turn the 277 into a boat anchor, and then something stirred way back in the memory banks - Back in 1983, I had a Maxair Hummer with a 277 on it, and when it was new, the engine ran properly with factory jetting. After several months of flying and getting well broken in, it got wonky. Kind of like this one. Something we noticed on this engine, you could not get the EGT's above 950 under load. If you went smaller on the needle jet, then it would not accept throttle. If you lowered the jet needle lower than normal, it would not accept throttle. The low and mid range was too lean. So we took off the intake silencer, took everything back to stock jetting. No improvement. The symptoms were constant: would not run normally between 5200 and 5800. It would run fast, or it would run slow, but not at a usable rpm. So we decided to go bigger on the low end jets and and then see if it would accept smaller top end jets. Bingo! Stock jets are a 148 main, a 2.72 needle jet, an 8L2 jet needle in the middle #2 clip position, and a 45 idle jet. Now running a 145 main jet, a 2.70 idle jet, an 8G2 jet needle with the clip in the bottom #3 position, and a 50 idle jet. Set the Ivoprop so that it turns 5900 on climbout and it runs perfect, EGT stays about 1025, good throttle response. Finally. -------- Richard Pike Kolb MKIII N420P (420ldPoops) Kolb Firefly Part 103 legal Kingsport, TN 3TN0 Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=489131#489131 ________________________________ Message 2 _____________________________________ Time: 11:39:46 AM PST US Subject: Kolb-List: Re: 277 keeps falling off the pipe From: "George Alexander" Richard Pike wrote: > IT WORKS! > > ...S ...N ...I ...P > > Finally. Flaming enthusiasm, backed up by horse sense and persistence, is the quality that most frequently makes for success. Dale Carnegie -------- George Alexander FS II R503 E-LSA N709FS http://www.oh2fly.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=489132#489132 ________________________________ Message 3 _____________________________________ Time: 04:27:38 PM PST US From: "Stuart Harner" Subject: RE: Kolb-List: Re: 277 keeps falling off the pipe Awesome troubleshoot and fix. Congratulations on a job well done. Definitely one for the archives! -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Richard Pike Sent: Wednesday, May 08, 2019 12:29 PM Subject: Kolb-List: Re: 277 keeps falling off the pipe --> IT WORKS! Over the last couple of weeks we tried taking 2" off the prop length; no improvement. But a 60" prop is still plenty of prop for a 277, so no real harm done. We were about ready to turn the 277 into a boat anchor, and then something stirred way back in the memory banks - Back in 1983, I had a Maxair Hummer with a 277 on it, and when it was new, the engine ran properly with factory jetting. After several months of flying and getting well broken in, it got wonky. Kind of like this one. Something we noticed on this engine, you could not get the EGT's above 950 under load. If you went smaller on the needle jet, then it would not accept throttle. If you lowered the jet needle lower than normal, it would not accept throttle. The low and mid range was too lean. So we took off the intake silencer, took everything back to stock jetting. No improvement. The symptoms were constant: would not run normally between 5200 and 5800. It would run fast, or it would run slow, but not at a usable rpm. So we decided to go bigger on the low end jets and and then see if it would accept smaller top end jets. Bingo! Stock jets are a 148 main, a 2.72 needle jet, an 8L2 jet needle in the middle #2 clip position, and a 45 idle jet. Now running a 145 main jet, a 2.70 idle jet, an 8G2 jet needle with the clip in the bottom #3 position, and a 50 idle jet. Set the Ivoprop so that it turns 5900 on climbout and it runs perfect, EGT stays about 1025, good throttle response. Finally. -------- Richard Pike Kolb MKIII N420P (420ldPoops) Kolb Firefly Part 103 legal Kingsport, TN 3TN0 Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=489131#489131 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-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/kolb-list Browse Digests http://www.matronics.com/digest/kolb-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.