---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Fri 12/17/10: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:25 AM - Happy First Flight Day (Richard Girard) 2. 07:01 AM - Re: Rough Running 912 (lucien) ________________________________ Message 1 _____________________________________ Time: 06:25:59 AM PST US Subject: RotaxEngines-List: Happy First Flight Day From: Richard Girard Wilbur Wright invented flight controls, with Orville invented aircraft propeller theory, and developed the first real flight test program. Until 1908 all the others were just jumping off the roof with an umbrella. Happy First Flight Day folks. Rick Girard -- Zulu Delta Kolb Mk IIIC 582 Gray head 4.00 C gearbox 3 blade WD Thanks, Homer GBYM It is not bigotry to be certain we are right; but it is bigotry to be unable to imagine how we might possibly have gone wrong. - G.K. Chesterton ________________________________ Message 2 _____________________________________ Time: 07:01:28 AM PST US Subject: RotaxEngines-List: Re: Rough Running 912 From: "lucien" Thom Riddle wrote: > Hugh, > We ran our Allegro with vent lines tucked into the float-bowl bail too for the entire time we owned it, with no problems either. It is not essential to change that in any way as long as you don't have any really odd airflow under the cowl and therefore unusual pressure distributions. However, routing the vent line to the inside of the air filter is the way that Jabiru does theirs and it does eliminate any spurious pressure issues that might arise in some installations. > > As Lucien said, black plugs are common after a few minutes of low rpm running. The only way to get an accurate plug reading on engines with Bing CV carbs is to cut the engine off at altitude at cruise rpm, do a dead stick landing and check the plugs. I am not recommending this, of course, though I have done it myself. BTW, another way that I mentioned before that you can do without pulling the plugs is just examining your exhaust baffles. What I've found is the high-power mixture will be reflected in a baffle, but a rough gauge of what you're getting at low power settings will collect on inside of the exhaust outlet. I.e. the exhaust pipe will usually have a fair buildup of black soot but the exhaust baffle will hopefully be a light antique white. When I was doing my carb sync after getting my rebuilt carbs back a few months ago, I did a lot of running at idle and 2000 to 3000 on the ground. The baffle inside my exhaust got pretty tarred&feathered with soot. but after going up and doing a few touch and goes the baffles were nice and white when I got back down. The other discovery is that when I finally got the idle mix set on the "knee", the idle EGT's ended up around 1050 to 1100F. I was at about 800 to 900F before, which I didn't know was just slobbering rich.... The idle speed also came up about 50 rpm as I leaned out the mix. Course this is all at my 7000' MSL and the density altitude is usually 8000' or more, so you kind of have to make adjustments like this up here. At sea level, you're pretty much just bolt the motor on and don't screw with it.... Oh PS: the fight I started on the Kolb list wasn't about the 912 vent lines (it was about the 2-stroke pulse line length). LS -------- LS Titan II SS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=323650#323650 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-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/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-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.