Who's running high Octane Gas ??

I've been running 93 pump gas in my bike since I bought it. A friend of mine just bought an 01' YZ 426 that he's running Sunoco 100 in. He swears that his bike runs better on this gas than 93 pump, AND 110 cam2. I know you are supposed to lean the jetting when you run high octane (unless it's oxygenated), but with the BK mod I had to richen the jetting a little.

Is anyone running non-oxygenated high octane gas that they think makes their bike run better?

Any advice on this topic would be great.

P.S. I'm at sea level to 2000 ft.



I've used VP C-12 with good results. It's non-oxygenated and easy to tune. For the last several months, I've been using MR2 with even better results. MR2 gives a crisper throttle response and better high RPM power. I think MX Tuner uses C-14 with good results as well. Phillips makes a couple of fuels that perform well in the 426. If my memory is correct, B-35 is the best choice from Phillips. You can't just dump these fuels into your tank and expect instant improvements. You must be willing to jet accordingly to realize any improvements. Typically, when switching from pump fuel to an oxygenated fuel, richer jetting is required. Leaner for non-oxygenates. These changes in jets are usually small. . . maybe one or two sizes. My experience with these fuels is two sizes on the main and one size change on the pilot and then one size change on the main between summer and winter.

I use Unocal 76 110. It is the same fuel that Nascar uses. It is very similar to VP C-12 in all critical areas.

Jetting is very important to get maximum performance out of what ever fuel you use (pump or race). I like the consistency I get from race gas. Here in So. Cal. they make us the test rats for all the smog restrictions placed on pump gas. You can never get the same performance from the pump can after can.


Sorry, double post.

[ February 12, 2002: Message edited by: yzernie ]

Where do you guys buy these types of high octane?

I get the good stuff at the local race track (Sunshine Speedway in St. Pete FL). I have also used a local "speed shop". Best way to locate the fuel is to just ask someone at the track you ride.


Some Sunoco's have the 100 octane race gas, other than that, I get 110 "cam-2" at the local "speed" shop.

How do you like your Thunder Alley pipe? Where did you noctice a difference between it and stock?

John H.


Love the TA pipe. The 2 things I noticed most are that it's harder to keep the front wheel down and it revs forever. I did have to go to a 48 pilot to stop the backfiring and bog down low, once I put the pipe on. I was already running a 168 main. Might look into the ceramic coating like some of the others have done. Definitely need to do something.

I run half 110 "cam 2" and half 93. I run that in any bike I own. Cam 2 is $4 per gallon at a local Exxon station here.

I run MR-2 in my bike and also run the Yosh TI pipe and header and the airbox/boot. MR-2 requires you jet richer that the typical C-12, but is about the same jetting as pump gas if the bike is not modified. The bike runs better but is more difficult to start when it stalls. When I raced Millville BK told me to run this set-up as it would net the best performance for the $$$.



IBWFO: I am on the exact same page as you but with one small exception. After a stall, my engine fires quickly if I use the hot start button to clean out the cylinder. MR2 works extremely well in my machine. Throttle response is almost TOO crisp.

I couldn't be happier with the way mine starts. The most I have ever kicked it is 3 times. When hot, it starts first kick with the hot start button. I'm super impressed with it. Coming from a bike with electric start, I was a little weary of buying a bike that had somewhat of a bad reputation on starting. It starts just as easy, if not easier, than any two stroke I've had.

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