---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Wed 03/18/09: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:49 AM - Re: 503 Exhaust Gasket replacement (cristalclear13) 2. 06:51 AM - Re: 503 Exhaust Gasket replacement (cristalclear13) 3. 07:20 AM - Re: 503 Exhaust Gasket replacement (lucien) ________________________________ Message 1 _____________________________________ Time: 06:49:49 AM PST US Subject: RotaxEngines-List: Re: 503 Exhaust Gasket replacement From: "cristalclear13" cicrn(at)telus.net wrote: > You will have to replace the gaskets but there is likely more to it. > Every Rotax 2-stroke I have had has warped the Y manifold after a few > hours of running. The fix is to plane the mating surface of the Y > pipe. My Rotax Service Centre rep told me to take the Y pipe off and > plane on a flat belt sander. Do it once and it should be good for the > life of the engine (manifold). It worked for me every time, no more > leaks. Another issue is when you have the cylinders off for any > reason, you need to make sure they true. The exhaust ports need to be > in plane (in line). > Regards, > Joe > > Joe, Looks like you might have something there. I replaced the outside gaskets and flew her, and there was still some leaking on the front exhaust port. I may also have to take the cooling shroud off and replace the inside gaskets (thanks to Gerry Olenik for letting me know where the second gasket went since it wasn't in the diagram). Replacing the outside gaskets ended up not being as easy a job as I thought it would. Two of the bolts wouldn't start so we tapped the holes and died the bolts, then it went much smoother. When I flew, my takeoff RPM was only going up to 6000 when it normally goes up to 6200. I don't see how anything we did could be related to that though? -------- Cristal Waters Kolb Mark II Twinstar Rotax 503 DCSI Read this topic online here: http://forums.matronics.com/viewtopic.php?p=235082#235082 ________________________________ Message 2 _____________________________________ Time: 06:51:57 AM PST US Subject: RotaxEngines-List: Re: 503 Exhaust Gasket replacement From: "cristalclear13" cristalclear13 wrote: > > I may also have to take the cooling shroud off and replace the inside gaskets (thanks to Gerry Olenik for letting me know where the second gasket went since it wasn't in the diagram). > > Correction to that...thanks to John Hauck for letting me know where the second gasket went. Gerry told me I could try replacing the outside gaskets first. -------- Cristal Waters Kolb Mark II Twinstar Rotax 503 DCSI Read this topic online here: http://forums.matronics.com/viewtopic.php?p=235083#235083 ________________________________ Message 3 _____________________________________ Time: 07:20:07 AM PST US Subject: RotaxEngines-List: Re: 503 Exhaust Gasket replacement From: "lucien" cristalclear13 wrote: > > cristalclear13 wrote: > > > > I may also have to take the cooling shroud off and replace the inside gaskets (thanks to Gerry Olenik for letting me know where the second gasket went since it wasn't in the diagram). > > > > > > > Correction to that...thanks to John Hauck for letting me know where the second gasket went. Gerry told me I could try replacing the outside gaskets first. The leaking exhaust at gasket syndrome, if replacing the gaskets and torquing the bolts correctly (195 in/lbs when cold) doesn't cure it, is usually caused by the poor support of the muffler and/or way too strong springs holding the tubing together. The muffler mount has to support the can so that the manifold and elbows don't take the weight of it. Also, the springs used on the elbows have to be loose enough to allow the elbows to flex a bit, isolating the rest of the muffler from the manifold. What sometimes happens otherwise is the manifold manages to rock ever so slightly under the vibration of the motor, deforming the gaskets or worse, causing the black stuff to still leak even when the bolts are torqued down. Replacing all the gaskets outside and in and torquing the bolts will usually fix it if no warpage anywhere has occurred. The exhaust manifold bolts should be checked frequently with a torque wrench at first (i..e on a cold motor before every flight for the first 5 or 10 hours or so) as the gaskets settle in. LS -------- LS Titan II SS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=235086#235086 ------------------------------------------------------------------------------------- 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.