---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Tue 12/21/10: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:26 AM - Re: Re: Octane degrading with storage time (Matt Tucciarone) 2. 05:23 AM - Re: Octane degrading with storage time (Thom Riddle) ________________________________ Message 1 _____________________________________ Time: 04:26:27 AM PST US From: "Matt Tucciarone" Subject: Re: RotaxEngines-List: Re: Octane degrading with storage time ?I have been flying a 912S for about 7 years now. I have had gas in the plane for longer than 4 weeks. As soon as I buy gas, I add Stabil to it even if I plan to fly that day. I have never had a problem. I have never seen any varnishing in my float bowls. My engine has never even hiccupped. I learned this at a Rotax seminar taught by Phill Lockwood. -----Original Message----- From: John Fasching Sent: Monday, December 20, 2010 9:56 PM Subject: Re: RotaxEngines-List: Re: Octane degrading with storage time Thanks, Roger. I was not looking to increase octane in the mogas (91) but wondered about 'rejuvenating' 91 that has been in the plane longer than I would be comfortable with...says something over 3 weeks. If the weather would cooperate I could keep the gas fresh by simply flying a lot, which is what I want to do, but winds have been so darn bad of late that flying wasn't worth the beating you'd take doing it. I will note your recomendations and follow them. Thank you. John ----- Original Message ----- From: "Roger Lee" Sent: Monday, December 20, 2010 7:29 PM Subject: RotaxEngines-List: Re: Octane degrading with storage time > > Hi John, > > I wouldn't keep fuel longer that 4 weeks. That's what Rotax recommends. No > matter what type of container you store fuel in it will evaporate and or > have octane degradation and loose other additives. Don't store any more > than you will use in that time and don't fill your plane up if you plan on > letting it set for months. If you plan on not flying for a couple of > months just drain the fuel at a low point bleed. Octane booster won't work > for us and unless you feel like throwing the dice with $10-$12k in rebuild > cost then just use fresh fuel. It will drop down to to 87-88 octane before > you know it. If that happens either drain and put fresh 91 oct. in or add > at least 50% of 100LL. > > -------- > Roger Lee > Tucson, Az. > Light Sport Repairman - Maintenance Rated > Rotax Repair Center > Home 520-574-1080 TRY HOME FIRST > Cell 520-349-7056 > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=323978#323978 > > ________________________________ Message 2 _____________________________________ Time: 05:23:36 AM PST US Subject: RotaxEngines-List: Re: Octane degrading with storage time From: "Thom Riddle" I've heard this "octane degrades over time" story a lot over the years. Several years ago I researched this and found (and lost) a petroleum engineer's explanation of how gasoline goes bad over time. He explained all of this in layman's terms and debunked the "octane degrades" part, i.e. octane does not degrade. However, gasoline does go bad for other reasons. I wish I could find this but have failed to do so, so far but will keep looking. However, I did find the following which I believe to be a reliable authoritative source (but can't guarantee that) which does not even mention octane but does describe how gasoline does go bad over time. http://www.straightdope.com/columns/read/2668/why-does-gasoline-go-stale-so-quickly As this source recommends, I have been adding Sta-bil to my stored gasoline beginning in the late fall when my flying frequency falls off dramatically. It works well in my experience. -------- Thom Riddle Buffalo, NY (9G0) Kolb Slingshot SS-021 Jabiru 2200A #1574 Tennessee Prop 64x32 Everyone is entitled to his own opinion, but not his own facts. Daniel Patrick Moynihan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=324000#324000 ------------------------------------------------------------------------------------- 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.