Question about gas

Model Specific Discussions about the Sling TSi.
hipsterdad
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Joined: Tue Feb 02, 2021 3:52 pm
Location: SF Bay Area

Question about gas

Post by hipsterdad »

Hi!

Potential new owner/builder here. I'm trying to do some research and figure out details/operational issues. How do you fuel your TSi? I read that the Rotax 915 works better with regular automobile non-leaded gas (mogas). But that's not always available at airports. My base very likely will be KHWD and they don't have, AFAIK, mogas only jet and 100LL. If I could get a hangar I could potentially get a large tank with a pump, but getting a hangar anywhere in the bay area is very hard. Even then, if I want to do a long haul, how would I refuel?

Has anyone run the 915 with 100LL only? what are the maintenance problems I could face in the long run?
Cluemeister
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Location: Tennessee

Re: Question about gas

Post by Cluemeister »

Lots of people run the Rotax engines with 100LL. I avoid it unless I'm on a long cross country.

I haul 91 E free mogas to the airport, as my FBO does not allow me to store fuel in the hangar. I use the Flo Fast 10 1/2 gallon tanks, with the Flo fast pump. I also use a Mr. Funnel.

https://flofast.com
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ibgarrett
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Re: Question about gas

Post by ibgarrett »

Hey Hipster,

I started my flying in LSA's with the Rotax 912 engines, which have the same fuel requirements as the 915. Basically you can run either Mogas or 100LL or a mix thereof. The main difference is if you're running 100LL you'll want to do the oil changes more frequently as its a dirtier fuel. I'm in the same boat as there isn't Mogas on any nearby field, so my plan is going to be trucking it in for any fill ups at my home airport and when I do any xcountry flying I'll certainly search out any Mogas airports, but i suspect I'll just have to go with the 100LL and change the oil when I get back home.

I know out in Torrence they have a small fuel truck that they take over to Costco for all their 912, 914 and 915 engines, even with ethanol. The real killer on ethanol is the airplane sits for a long time. Which in my mind is even that much more of a reason to "gosh darn I have to go flying" :)

As for the fuel transport, check out Trent's video at He's running the same 915 engine.

I also, personally am thinking there may be a business opportunity to putting in a self-serve Mogas pump at my home airport. I just have to look into the costs..

Brian
Brian Garrett
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ibgarrett
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Re: Question about gas

Post by ibgarrett »

Cluemeister wrote: Tue Feb 02, 2021 5:13 pm Lots of people run the Rotax engines with 100LL. I avoid it unless I'm on a long cross country.

I haul 91 E free mogas to the airport, as my FBO does not allow me to store fuel in the hangar. I use the Flo Fast 10 1/2 gallon tanks, with the Flo fast pump. I also use a Mr. Funnel.

https://flofast.com
I always get a kick out of the "no fuel in the hangar" restrictions... uhm what's in the wings of every airplane?

yeah yeah.. I know... :)
Brian Garrett
hipsterdad
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Location: SF Bay Area

Re: Question about gas

Post by hipsterdad »

thanks everyone! it seems then that using 100LL is not a mortal sin and would just require more careful care of the engine (changing oil more frequently). I'll keep looking the thread in case anyone else has more comments on this.
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PhilipRueker
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Re: Question about gas

Post by PhilipRueker »

One more thing to add, a lot of people running Rotax engines on 100LL will add an additive Decalin to scrub some of the lead deposits to keep the engine cleaner.
Building a Sling TSi in my Garage.
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MTJ
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Joined: Mon Dec 09, 2019 7:53 am
Location: 1L9

Re: Question about gas

Post by MTJ »

If you have a truck there are fuel tanks that you can get that will fit in your bed. More than enough to fill up your new pretty plane.

https://www.calranch.com/rectangular-li ... 0-gal.html

My airport is pretty helpful. I am building a 350 gallon tow trailer with a pump/filter system that I can park on the airport.
KEIK_flyer
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Re: Question about gas

Post by KEIK_flyer »

I've been lucky enough to have about 100 hours flying a Gobosh 700 which had a 100hp Rotax 912 ULS. While it'd burn 100LL without any real trouble, the oil came out filthy when it was changed. The BRP certified tech that worked to keep them running *strongly* preferred running E0 Mogas in Rotax. He didn't like the lead of 100LL because it can sludge up the gear reduction unit. He was ok with E10 mogas if you're going to burn it straight away; otherwise the gas might sour due to the hygroscopic nature of ethanol.

For me personally, I'm going to use a transfer tank in the bed of my truck to get E0 from the Maverik up the street. My home base took out the Mogas pump when they rebuilt the tank farm to triple Jet-A capacity. I use one of Flo n' Go tanks to fuel the tractor here on the farm and its worked great thus far. Considering the price difference between MoGas and 100LL, I should make up the cost of the tank on the 2nd or 3rd fill.
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ibgarrett
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Re: Question about gas

Post by ibgarrett »

KEIK_flyer wrote: Thu Feb 11, 2021 8:39 am I've been lucky enough to have about 100 hours flying a Gobosh 700 which had a 100hp Rotax 912 ULS. While it'd burn 100LL without any real trouble, the oil came out filthy when it was changed. The BRP certified tech that worked to keep them running *strongly* preferred running E0 Mogas in Rotax. He didn't like the lead of 100LL because it can sludge up the gear reduction unit. He was ok with E10 mogas if you're going to burn it straight away; otherwise the gas might sour due to the hygroscopic nature of ethanol.

For me personally, I'm going to use a transfer tank in the bed of my truck to get E0 from the Maverik up the street. My home base took out the Mogas pump when they rebuilt the tank farm to triple Jet-A capacity. I use one of Flo n' Go tanks to fuel the tractor here on the farm and its worked great thus far. Considering the price difference between MoGas and 100LL, I should make up the cost of the tank on the 2nd or 3rd fill.
Hey KEIK - that's where I learned to fly out of. I'm out of KBJC now. I was around there when they had the Mogas tanks as well back with Skyraider. I'm just trying to figure out if the FBO's just don't want the extra tank because they can't make any money off of them, or if there isn't the demand. And if there isn't the demand I'm also trying to figure out if the build it they will come or if it's just the high DA here that nukes so much of the Rotax engines... but there are other engines out there that support Mogas.

My plan is to truck in my Mogas for the local stuff - and just have to deal with it when I go x-country. Basically starting out with a fresh oil change and do one when I get back, unless I'm gone longer than 25hrs of flying and then I'll do something in the field.
Brian Garrett
KEIK_flyer
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Re: Question about gas

Post by KEIK_flyer »

Jason and Rachelle have a business to run so I can't fault them for expanding Jet-A. The local skydiving company fills their turbine twin otter and B200 multiple times a day when the wx is good, Flight for Life *and* the Colorado ANG use those tanks for their helos so they're doing something right.

I'm with you on the gas plan. Hudson had Mogas for a while but I don't see it updated on AirNav any more.
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