---------------------------------------------------------- JabiruEngine-List Digest Archive --- Total Messages Posted Wed 01/26/11: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:08 AM - Re: Carb Jetting (Martin Hone) ________________________________ Message 1 _____________________________________ Time: 12:08:35 AM PST US Subject: Re: JabiruEngine-List: Carb Jetting From: Martin Hone Hi Tex & Bob, Your comments could not have come at a better time. I have just checked the main jet on a Bing fitted to a J230, and despite being marked as #255, it measured at #250. I have since reamed it to #260 Cheers Martin On Wed, Jan 26, 2011 at 10:58 AM, Tex Mantell wrote: > Bob, I had almost the same problem when trying to rejet my carb. The jets > from bing and others are not the actual sizes marked on the jets. Some are > larger then marked and some are smaller then marked. Take a good set of > drills and check each one. After I found this out I would get the result > expected when changing a jet. Tex > > ----- Original Message ----- > > From: BobbyPaulk@comcast.net > To: jabiruengine-list@matronics.com > Sent: Tuesday, January 25, 2011 11:35 AM > Subject: JabiruEngine-List: Carb Jetting > Mike > My first carb was running EXTREMELY rich on the standard jetting and nothing > I did would lean it out. The soot would build up in the exhaust pipe and the > plugs were covered as well. I was cleaning the plugs every 5 or 6 hrs. > Jetting, changing float level, and the inlet needle valve did not make any > difference. Make sure you are using the newer black floats. I know for a > fact that the original white floats could not shut off the fuel flow at 1.7 > psi on that carb. > My second carb with the black floats was running extremely lean with the > standard jetting. ( Go figure ) When I went into it I discovered it had a > 250 main jet in lieu of the standard 255. I have since re jetted to the 255 > main and then up to a 260. Also I have upped the needle jet in stages up to > a bored out 290 to 295. I have finally got it running some where in the ball > park with no adverse change in fuel consumption. > I do not understand how the same size and make carb can give such different > performance with the same parts except for the floats. > > At cruise settings my front two cylinders are running 150 deg. hotter EGT ( > 1340 ) than the rear ( 1190 ~ 1200 ) with the middle two in between. CHT on > the front cylinders are relatively cold 250 ~ 260 and rear cylinders right > at 300. I had to modify my Ram Air ducts, get rid of the butterfly baffles > on top, and make Lycoming type baffles on the bottom of the cylinders to get > to this point. > > Bobby > 113 hrs. > 601 XL > > > href="http://www.matronics.com/Navigator?JabiruEngine-List">http://www.matronics.com/Navigator?JabiruEngine-List > href="http://forums.matronics.com">http://forums.matronics.com > href="http://www.matronics.com/contribution">http://www.matronics.com/c > > ________________________________ > > No virus found in this message. > Checked by AVG - www.avg.com > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message jabiruengine-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/JabiruEngine-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/jabiruengine-list Browse Digests http://www.matronics.com/digest/jabiruengine-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.