---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Fri 06/20/08: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:33 AM - Re: Dry Black velvet Plugs (Thom Riddle) 2. 05:08 AM - Re: Dry Black velvet Plugs (Rich L) 3. 07:07 AM - Re: Dry Black velvet Plugs (lucien) 4. 02:51 PM - Re: Dry Black velvet Plugs (Roger Lee) 5. 02:56 PM - Re: average water temp of 912/914 (Roger Lee) 6. 03:12 PM - Re: Exhaust Spring (Roger Lee) ________________________________ Message 1 _____________________________________ Time: 04:33:19 AM PST US Subject: RotaxEngines-List: Re: Dry Black velvet Plugs From: "Thom Riddle" Don G. I had the black dry plug problem on both plugs on #1 cylinder only and it took me a very long time to determine the cause. I had very similar operating conditions too. I finally found a small gage white wire somewhere in the ignition system that was not completely broken but partially so. I repaired it and that fixed the problem. I'm still not sure where schematically the partial break was in the diagram but repairing it did fix the problem. It is still a mystery to me how that single white wire could cause BOTH plugs on a single cylinder to blacken. -------- Thom Riddle N221FA Allegro 2000 912UL N197BG FS1/447 -------------------- It has been said that man is a rational animal. All my life I have been searching for evidence which could support this. - Bertrand Russell Read this topic online here: http://forums.matronics.com/viewtopic.php?p=188737#188737 ________________________________ Message 2 _____________________________________ Time: 05:08:50 AM PST US Subject: RotaxEngines-List: Re: Dry Black velvet Plugs From: "Rich L" I have had the same problem on my 912uls since 0 hrs. I also screwed the mixture in 1/4 turn with no change. I have balanced my carbs twice now and the two forward cylinders still have the "black velvet plugs". It continues to run great with 150 hrs on it now and all the numbers are well within specs (EGT,CHT, Oil & Water Temp, etc). Read this topic online here: http://forums.matronics.com/viewtopic.php?p=188739#188739 ________________________________ Message 3 _____________________________________ Time: 07:07:15 AM PST US Subject: RotaxEngines-List: Re: Dry Black velvet Plugs From: "lucien" Rich L wrote: > I have had the same problem on my 912uls since 0 hrs. I also screwed the mixture in 1/4 turn with no change. I have balanced my carbs twice now and the two forward cylinders still have the "black velvet plugs". It continues to run great with 150 hrs on it now and all the numbers are well within specs (EGT,CHT, Oil & Water Temp, etc). I had this problem on my 912uls and there were 2 causes: - overly rich idle, I have to run my idle mixture screws in 1/2 turn from the recommended setting (1 turn out overall). - carburettor vent lines running outside just tucked into the float bowl spring. The vent lines have to be connected either to the intake airbox if you have one or routed into the air filters if you run those. The carburettors will run rich (and very much so at higher altitudes) unless the vents are at the same atmospheric pressure as the intakes in front of the venturis. This requirement is in the Rotax documentation. I bought some brass fittings at lowes and put them into holes in the back of my air filters. Fixed the rich running completely. The cylinders closer to the gearbox do run a little richer than the other two on my motor as well, probably due to slightly different lengths of the intake runners for the two banks of cylinders...... LS -------- LS FS II Read this topic online here: http://forums.matronics.com/viewtopic.php?p=188752#188752 ________________________________ Message 4 _____________________________________ Time: 02:51:32 PM PST US Subject: RotaxEngines-List: Re: Dry Black velvet Plugs From: "Roger Lee" Hi Guys, The length of the intake manifolds combined with each of our different engine setups in different planes can cause our plugs to look different and even have that dry black velvet coating. You won't have that when you are running at operational speeds (i.e. 4800-5200rpm). This is usually caused in the low rpm range. There can be more than one cause. Try one cure at a time until it goes away. If it doesn't don't panic your engine still runs good as many people will attest to. -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Service Center 520-574-1080 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=188820#188820 ________________________________ Message 5 _____________________________________ Time: 02:56:09 PM PST US Subject: RotaxEngines-List: Re: average water temp of 912/914 From: "Roger Lee" 180F-220F is very normal for this time of year. If you are using a 50/50 coolant then 248F is max. In the winter it might be lower in the 165F range. In the winter the warmer the better (i.e. 180F-220F) -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Service Center 520-574-1080 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=188821#188821 ________________________________ Message 6 _____________________________________ Time: 03:12:06 PM PST US Subject: RotaxEngines-List: Re: Exhaust Spring From: "Roger Lee" Roughly how many hours on each set of springs? Like Guy stated, make sure you use a nice thick wide bead of hight temp silicone pressed into and on each spring. When they are getting worn through then the mounting loops and the springs just have to be changed. Make sure all of you have these springs safety wired. The wire goes through the center of the spring and around each mounting loop. The safety wire should be slightly lose as it is not meant to hold the exhaust together and need to be able to move some. The safety wire keeps the springs from going places you don't want them if they break or come off. Use the .041 wire. Are the springs strung too tight? -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Service Center 520-574-1080 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=188823#188823 ------------------------------------------------------------------------------------- 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.