Race Gas

21 replies to this topic
  • Kenaroo

Posted April 11, 2002 - 04:22 PM


I know there has been alot of post about race gas and the debate to use it or not. I thought I would let you guys know about my results.

Bought a used 1999 yzf 400 about 3 weeks ago. very clean and in great shape. the guy stated he used race gas in it all the time. I haven't check the jetting and have just be getting used to riding the bike.

I made the change to super unleaded to save a few bucks on the gas and listen to most of the post of everyone stating that it didn't make much of a differnce.

I'm sure it has alot to do with carb jetting but this old thing didn't like the change. Didn't like starting. It would take 8 kick to get it lit then It would backfire and stall. when warming up I couldn't turn the throttle at all because it would just cough and die. It would run fine after it warmed up but how frustrating.

Changed back to race gas and the thing started on the 2nd kick and run awsome.

I'll be using race gas for now on. even if i'll cost me 5 bucks a gallon.

Just my 2 cents.

  • robswr426

Posted April 11, 2002 - 05:02 PM


goto the airport and get some ave gas and mix it with super unlead 1/2 and 1/2 saves a lot of $ and still gives the kick you like

  • therapture

Posted April 11, 2002 - 07:56 PM


Originally posted by robswr426:
goto the airport and get some ave gas and mix it with super unlead 1/2 and 1/2 saves a lot of $ and still gives the kick you like

No no no...av gas is NOT meant for dynamic throttle conditions. It also contains additives such as de-icers and other things to limit moisture absorption.

Think about it..planes fly at high altitudes, cold temperatures, and FIXED throttle settings.

Get race gas, say 110 octane, and mix it 50/50 with premium pump gas, and you might have the mix you need at half the cost...

Forget av gas....

  • txthumper

Posted April 12, 2002 - 02:00 AM


av gas is made for high altitude and low rpm..which we are neither..better off running something like vp c-12, or sunoco..

  • Hootna

Posted April 12, 2002 - 03:39 AM


Race Gas is great for compensating for bad jetting but at $5 a gallon I think I would personally try to get my bike jetted correctly. Also if your bike is 3 years old and has never had a top end or ring job it probably wont start very easy even if the jetting is spot on.

Folks there are smarter ways of spending your money. I by 4 gallons of 76 110 a week for my 2 stroke due to modifications at $5 a gallon. That is over a $1000 bucks a year but it is necessary. Save your money to buy jets a piston and rings.

My 250F runs like a bat out of hell on Super Unleaded. I have never and will never run RaceGas in this bike because it doesnt need it.

Good Luck.


Posted April 12, 2002 - 07:00 AM


i use vp octane booster in my fuel,i cant remember how many octane points it rasies the fuel,but it works great and dont cost as much to use as race fuel, my 400 dont like straight pump gas either...jimbo

  • Shawn_Mc

Posted April 12, 2002 - 07:16 AM


Race fuels have lower specific gravity values. Because of this, an engine that runs or acts lean on pump fuel will richen up with most racing fuels. So a hard to start, cold blooded, pain in the ass, will be more docile on the race gas. And it never hurts to have a more stabil fuel when your dealing with 12.5-1 compression ratios either. If you can afford it, do it. If not, you'll just end up with a stronger right leg!

  • sirthumpalot

Posted April 12, 2002 - 09:28 PM


Mayb it's a 400 thing but my '01 426 starts and runs great on super unleaded. Usually 2-3 kicks for the first start of the day, 1 kick all day long after that. I'm sure race gas runs great (I've never tried it) but the way this thing runs on pump gas I cannot justify the hassle to change.

  • Oregon_Thumper

Posted April 12, 2002 - 10:27 AM


I have to agree. I have never used race gas and probably won't because my 2000 runs great on Chevron Super Unleaded.

  • txthumper

Posted April 12, 2002 - 12:12 PM


ive been using vp c12 in my 01 426..along with the blue wire trick my bike is alot easier to start..as far as the race gas, i dont think it is required due to the 3-d mapping..but...racegas runs cooler and burns cleaner..

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  • Boit

Posted April 12, 2002 - 04:17 PM


If there was ever a motocross bike that begged for the PROPER race fuel, it is the 426...and even more so with the 250F. Even avgas is better than pump swill. . . by a hair. To get the most performance from a 426, selecting the proper fuel AND jetting accordingly will yield very satisfying results. Pump gas just doesn't cut it when the engine gets above about 9000 RPM, plus it is inconsistent in quality from week to week at the same gas station. Does race fuel provide ground breaking performance increases in the 426? No. It simply allows this machine to perform at the top tier of it's design.

  • krazyq

Posted April 14, 2002 - 04:19 PM


Someone told me Race gas dammages the tiatanium valves.Is there any truth to this?

  • osheen

Posted April 14, 2002 - 07:41 PM


None of the F's need octane as much as they need "quality fuel" Unless you are having a hard time finding decent pump gas, the race gas is a waste of money unless you are trying to squeeze every last bit of performance out of it..

To think that Av Gas is better than pump gas is obsurd. It's about as far way from what the bike wants as diesel fuel.

  • lawdog

Posted April 15, 2002 - 08:37 AM


Not to start a war, but I vote for race gas, and the stuff I use is 15.00 a gallon. But I want all I can get, and it's worth every penny. Lawdog

  • meangreen75

Posted April 15, 2002 - 10:09 AM


Everyone has the prefences but I've been running pump gas in 00' since I bought it in dec of 99. That bike has never given me a single problem in the starting or running area. Not to brag but I've done two races recently where I was the first off the line on a dead engine start. Not a KTM or a Honda. This was four strokers only and there was a lot of suprised people there because the blue ones are typically still sitting there when the reds and oranges are making dust. Pump gas is the way to go if you've never had to mess with you jetting. I'm just doing what the manual recomends anyway. Haven't had a regret yet. That's my $.02

  • Victor_Delgadillo

Posted April 15, 2002 - 10:24 AM


Agree with Geen Men... i mean mengreen... sorry, meangreen..!!! :)

Sorry i'm smelling too much gas..!!! :D

  • Shawn_Mc

Posted April 15, 2002 - 10:51 AM


krazyq: no

  • John_Lorenz

Posted April 15, 2002 - 10:55 AM


I get real bad gas when I eat at the Super Tacaria in Hollister.

Are we talking about Gas or GAAAAAASSSSS

  • Boit

Posted April 15, 2002 - 03:51 PM


Avgas is not the optimum fuel for the "F's. It is merely a slight cut above pump gas in consistency if jetted accordingly. Yes, it has additives that don't help performance of the 426/250 high revving design, however, it IS better to use than relying on pump gas. To compare avgas to diesel is truly "obsurd" . . .as spelled.

If pump gas satisfies you, use it.

  • javelinmxer

Posted April 15, 2002 - 05:30 PM


I've used AV gas for the last three years, and had it lab tested. There are different types of av gas, and the kind I get is high quality. It is rated at 118 octane as well as oygenated and I have never fouled a plug in three years of using it. When I tried using Sunoco94 the bike ran like crap. Ran great as soon as AV gas was back in her veins. So put me down if you like, but I have no problems with the fuel I use.

[ April 15, 2002: Message edited by: javelinmxer ]

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