I put hundreds of hours on the Tripacer and KR using MoGas without a
problem but not any more.  I've purchased fuel (Shell) at a local
station that charged a higher price for "no-alcohol" fuel and found it
loaded with alcohol.  You can't trust the system on an issue like this. 
You might get rid of the alcohol but the gas is crap like Jeff found out
the hard way.  Check, double check, and practice engine out procedures.

Larry Flesner


What I discovered is that not all Alcohol Free 91 AKI gasolines are created 
equal.  This is part of my learning curve from moving to a new area of the 
country.  Now that I have a damaged aircraft, all kinds of people come crawling 
out of the woodwork to tell me about the one station that has good fuel.  Up to 
that point, I heard no mention of it.  

Now that I have found what appears to be a reliable fuel source, I fully intend 
to go back to running an 80% Mogas mix in my planes.  However, I would strongly 
recommend testing in a manner similar to the jar tests that I performed.  The 
test I referenced previously using fittings with cured pipe dope in them only 
took a few seconds to perform and is a strong indicator of the presence of 
additional chemicals that may be detrimental to your fuel system.  I would also 
perform the standard testing for presence of ethanol as well.  If the fuel 
passes both of those tests, I would deem it as fit to use in my aircraft.

In addition to the additional fuel testing, when I repair the other aircraft, I 
will be painting on a slosh coating compound on the inside of the tanks to 
further protect the tanks in the case of a similar fuel contamination situation 
in the future. I should mention here that Vinylester tanks are the safest way 
to go with composite tanks.  That was unknown when I built my KR, and my 
SuperCub already had glass tanks in it when I bought the project, so I used 
them.  However, even vinylester won't protect the rest of your fuel system from 
additives that may dissolve the pipe dopes or damage rubber compounds.  

While we currently have 100LL available as an expensive, overloaded with lead, 
but relatively safe fuel to burn.  It's demise is planned in the not too 
distant future.  The FAAs PAFI testing has already discovered interoperability 
issues between the Aeroshell and the Swift unleaded fuels.  Now most of the 
vendors, Swift, GAMI, and Phillips are all attempting to certify their unleaded 
fuels via STC rather than continuing the PAFI process, while Shell is now alone 
in proceeding with the FAAs PAFI initiative.  None of us know for sure that any 
or all of these fuels will be as kind to our fuel systems as 100LL, and some 
may have a different metal added as an octane booster that could be just as 
detrimental to engine valve guide life as the lead in 100LL.  One thing is for 
sure; The 100LL replacement fuel will be even more expensive than 100LL, but 
will be lead free, negating any reason to purchase it to mix with Mogas.  In my 
opinion, it's best to know what options are available other than the fuels 
being sold at the airport.

-Jeff Scott
Cherokee Village, AR

Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/.
Please see LIST RULES and KRnet info at http://www.krnet.org/info.html.
see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change 
To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org

Reply via email to