Sunoco GT Plus 104

[PMK]

Race Fuel Transformation

I purchased some Sunoco GT Plus 104 in a sealed five gallon steel container to try in the YZ426. I rode yesterday and after about 10 minutes the motor starts popping real bad going into the turns and also stalling. I figuire maybe the jetting is off so I pull the pilot jet and it's plugged solid and the carb has an ultra fine brown crud in the main jet cap. I pulled the bowl and find more crud. I cleaned the jets and bowl and ran it again hoping the previous fuel ( not the Sunoco ) was the problem and the GT Plus being new and put into a drained tank and carb would work ok. After cleaning the carb I ride it about 10 more minutes and the same thing, plugged pilot jet, but it runs good until the jet plugs up.
I get it home and flush the tank, petcock, cap vent, etc and disassemble and clean the carb. I filtered all the fuel from the tank thru layers of fabric and find a brown stain in all the filters. I put some fuel that had been drained into a white plastic cup, after several hours there is a brown sediment on the bottom. Just for grins I took some fuel that had only come from the Sunoco container and put it into a sister cup. After a while the new fuel has this brown crud. The fuel was new to me about a week ago and came in an unopened steel container and has been stored in the steel container until put into the tank that morning. Anyone have any thoughts as to why the fuel is changing? Also the Sunoco wasn't mixed with other fuel or any additives.
Thanks
PK

 

[Faded]

Originally posted by PMK
...and has been stored in the steel container until put into the tank that morning...PK

Maybe the steel container was rusty on the inside. I'd take it back and check with them.

 

[bclapham]

kind of ironic, but it sounds like the freshly sealed race gas may have been bad to start with!

 

[PMK]

I seriously doubt the can is corroded, looking thru the filler reveals a clean can. I checked with a friend I ride with that bought the same type fuel from the same place, with a slightly different batch number on the can and he doesn't appear to have the problems. In fact we drove to practice together and he rode an entire tank of fuel while I rode 15 minutes. I'm thinking bad fuel. I'll call Sunoco and see if they have a clue. The irony is that we both switched to the race gas after my friends CRF refused to start a week ago and it turned out to be bad fuel from Ammoco. Go figuire-it's most likely my turn for some stupid luck.
Any other thoughts are welcome.
Thanks
PK

 

[PMK]

Several days back I had posted about my fuel causing problems with blockage of the carb jets, and the fuel changing from clear blue to a stained brown. For whatever reason the original post vanished.
The cause of the problem with the fuel has been found. I spoke to the tech rep / chemist at Sunoco and found out that the GT Plus uses an octane additive that is quite sensitive to sunlight, and will cause the transformation that occurred in my YZ426. Since the fuel has been stored in sealed steel cans, and then poured from the steel can to the tank, it was unofficially decided but yet to be totally tested that the sunlight that was able to shine on the tank while riding caused the fuel to generate the precipitate and plug the pilot jet several times. My riding buddy with a Honda had no problems with his fuel. Two different cans bought a day apart. The Honda sports a black tank between the frame and covered with the shrouds, the Yamaha has a tank that will apparently let enough UV thru to cause the fuel to react.
After several carb cleanings and flushing the tank, petcock and fuel line I still am having the debris wind up in the carb and plug the pilot jet although it's happening less often. Whatever this is it truly creates a lot of havic, so I would only recommend GT Plus if you race at night without a headlite. The reaction in straight sunlight is about two minutes in a clear cup. The fuel did run well in the Honda.
PK

 

[PMK]

Per the Sunoco tech rep, this additive that precipitates is NOT used in the GT100 fuel, but IS used in the GT Plus 104.
PK

 

[whyzee]

I use the exact same fuel, uncut except for oil, in my yamaha and have never hat a problem. FYI, I have used the gt plus for over a year. :think:

 

[PMK]

For what it's worth, I took a small amount of the fuel from the Hondas can and it too precipitated with the same brown sediment. This fuel had never been placed into a tank.
The real test is to place a small amount of fresh fuel into the tank and let it sit for a little bit in the sun and see if it changes.
When I called Sunoco and explained to Art that I suspected bad fuel he immediately told me what I was finding, to which I agreed, he then explained about the precipitate.
Whzee, if you would, please take a small amount of fresh fuel and put it into a throw away clear cup. Set it outside in the sunlight and see if you also have the fuel react.
Thanks
PK

 

[23jayhawk]

So this is what we've come to - fuels so sensitive that they can only be used for indoor supercross and speedway. :|

 

[PMK]

Jayhawk, this fuel is not a motorcycle specific type fuel. Actually it's most likely more for the guys with hi performance cars that need unleaded fuel. I would prefer c12 but it's about an hour drive to get it. The Sunoco is on the way to work and about five minutes from home. I definately would not have bought this stuff had any of Sunocos publications said anything about detriment to the fuel by UV. I've already purchased the non reactive GT100 for use after I get all the crud out of my fuel system.
PK

 

[whyzee]

Originally posted by PMK
Whzee, if you would, please take a small amount of fresh fuel and put it into a throw away clear cup. Set it outside in the sunlight and see if you also have the fuel react.

I'll give it a look in the morning, and let you know the results.
BTW, where are you from? It will help to know your climate conditions.

Another thing to think about is the condition of the vendors storing area, pump equipment and how quickly he is turning the product. My stuff comes from the local circle race track, it's kept in a sealed trailer without light and he turns a 54 gallon drum every 2 weeks.

Looking at the distillation and gravity #'s for C12 and GT plus, they are almost the same, the plus side of C12 is buying sealed 5 gal containers which are shorter than my race jug and easier to store.

What kinda change do you spend for GT+?
Dave

 

[PMK]

Whyzee.
In response to your questions. I live in South Florida, and it has been fairly low humidity and cool (70's), but it has also been very clear with almost no cloud cover.
As for my vendor, he buys GT104 in 55 gallon drums direct from Sunoco in PA. then pours out eleven cans and seals them with the knock out cap and screw on cap. So the fuel isn't stored in tanks. Both the rep at Sunoco and the local dealer had the same story about the five gallon cans because I had suggested to the rep how it was a factory sealed can and he mentioned they only sell in 55's to my dealer.
The fuel numbers are quite similar and this was one reason for trying the GT104. For me to buy C-12 the vendor pumps it. If you want a five gallon can they fill it from the pump and close the lid. I haven't been down to Fort Lauderdale to see but I think they store below ground.
As for pricing, I was quoted $4.50 per gallon on C-12, the Sunoco GT100 and GT plus are just under $31.00 for the five gallon can.
After giving your previous post some thought, I think another factor to letting the UV into the YZ's tank is the fact I run no graphics at all on the tank, this can't help.
I am curious to see what your fuel did. I've gone back to pump fuel trying to flush the remaining crud from my tank. I rode a while yesterday and didn't plug the pilot jet, but there was trash when I drained the carb and pulled the main jet cap. I've never had any issues working with the YZF but at this point I could likely apply as a teh rep for Kei-Hin.
Thanks
PK

 

[whyzee]

I just checked the glass jar I left the fuel in today, and found no solidification result, but it was a high of 43 degrees here today. That does not mean that you're fuel is not having a breakdown. The reason I asked about your climate is exactly as I suspected, ... you're in a very warm climate for this time of year. What is the chance your tank is an aftermarket or is somehow decomposing? :think:

BTW, I pay $5.60 / gallon and thats pumped straight into my race jug. If I could get a fix on C-12 @ $4.50 I would be all over it.

 

[cujet]

I suspect the blue tank on the YZ426 is not capable of blocking any UV radiation. It actually makes sense due to the closeness of the color blue to the UV end of the spectrum. A red jerry jug (or Honda Gas tank) would seem to be just the right color to block UV!

I suggest using 50% Amoco and 50% Avgas! (just kidding)

Actually I have had the best result in consistency with local Amoco. Sorry to hear you had a problem with it. I prefer Chevron for the Turbo Miata, however the quality varies too much for my tastes.

Chris