i've rebuilt rm-z450's and kx450f's that customers ran 87 or 89 octane fuel in and broke the pistons in half!! like literally in half.

i think if your still anti-race fuel after all this...still buy a pail of r110 or c12 and mix a gallon to every three gallons pump just to be safe!

87-89 mr/2 octane isn't high enough for these bikes. At the very least 92 octane. Just to be safe 1 gallon of c12 to three of premium like Jensen said. That gets the motor octane up around 96.

I run premium pump gas, thats 92 I believe. Never had a knocking problem. When I tore the motor down at 60 hours, everything was still in spec and looked good. Granted I don't ride the bike to near it's potential, but every now and then I miss a shift and hit the rev limiter

I'm still more concerned about my filter leaking...I'm in the back behind you guys,gassin it like heck but a gear low..

IF YOU ARE DUMB ENOUGH TO PUT 110 IN A FOUR STROKE YOU DESERVE TO BLOW IT UP. you can run a lower octane fuel if you are smart enough to JET FOR IT. 110 has too high of a detonation temp to put in a 4- stroke you'll crack or break a piston in a few hours with it.you should run u-4 or a mix of c-12 with u-4 and 92, figure out your mix, jet, and race you'll be golden. regular maintaince bike should last at least 100hrs.

People, people, octane rating does not burn hotter, add power, or any other myths. It simply provides the fuel a chance to burn at the proper point in the combustion cycle. Here is the definition of octane number

The octane rating of a spark ignition engine fuel is the knock resistance (anti-knock rating) compared to a mixture of iso-octane (2,2,4-trimethylpentane, an isomer of octane) and n-heptane. By definition, iso-octane is assigned an octane rating of 100 and heptane is assigned an octane rating of zero. An 87-octane gasoline, for example, possesses the same anti-knock rating of a mixture of 87% (by volume) iso-octane and 13% (by volume) n-heptane. This does not mean, however, that the gasoline actually contains these hydrocarbons in these proportions. It simply means that it has the same autoignition resistance as the described mixture.

A high tendency to autoignite, or low octane rating, is undesirable in a spark ignition engine but desirable in a diesel engine. The standard for the combustion quality of diesel fuel is the cetane number. A diesel fuel with a high cetane number has a high tendency to autoignite, as is preferred.

It should be noted that octane rating does not relate to the energy content of the fuel (see heating value), nor the speed at which the flame initiated by the spark plug propagates across the cylinder. It is only a measure of the fuel's resistance to autoignition. It is for this reason that one highly branched form, or isomer, of octane (2,2,4-trimethylpentane) has (by definition) an octane rating of 100, whereas n-octane (see octane), which has a linear arrangement of the 8 carbon atoms, has an octane rating of -10, even though the two fuels have exactly the same chemical formula and virtually identical heating values and flame speeds.


Race fuel will give you more power but it is because it is oxygenated, burns more complete and allows for more precise jetting as it gives a more consistent blend. If you are not knocking though you do not NEED it.

STEVE YOU CAN RUN 110 IN A FOUR STROKE ALL DAY LONG AND NEVER HURT IT. matter of fact if the 110 is leaded it will probably help it. you just wont see any performance gains on a stock engine thats designed to run 92....maybe even lose power from the fuel burning slower almost like retarding to ignition timing.

NEVER MIX U-4.2 WITH ANYTHING!! ITS DESIGNED TO BE RUN STRAIGHT FOR THE PERFORMANCE GAINS...PLUS THE FUEL YOUR CUTTING IT WITH MAY NOT MIX PROPERLY.


OCTANE IS THE FUELS RESISTANCE TO DETONATION.

the higher the resistance the hotter the detonation, therefore you need to JET correctly, not once have you even mentioned that. you can run anything for fuel (yes) if you JET.

Steve that is not correct. Gasoline has a certain amount of energy (heat) if it doesn't knock that's what you get. Please read the definition again

It should be noted that octane rating does not relate to the energy content of the fuel (see heating value), nor the speed at which the flame initiated by the spark plug propagates across the cylinder

jensen why don't you give pro circuit a call then tell me that u-4 doesn't mix. they mix all sorts of vp fuels to get their desired mix and they jet for it. call 210-635-7744 that's the head office of vp, i just did. it's very interesting what they told me. you both should do more research.

jetting is definately important!! i called vp they said dont mix it with a fuel thats not compatible with that fuel. but all your doing is deluting the potency of the fuel...why would you do that?? keep running pump..


you keep saying u-4 do you mean u-4.2 ???

An Old time mechanik once told me if I put mothballs in my gas tank my bike will go better.
Do you know where to find a moths balls I've tryed for years and cant find them so we just ground them up whole and put them the tank wholy cow what difference!!! Works even better if you run hemp oil at 5 to one.

quote:

Originally posted by Vern#119:

Do you know where to find a moths balls

Sure Vern, they are right between their legs you have to look close cuz they are small..

You can thank me later

Started at the beginning of this thread and here's what I got...

So have you guys read that Oregon is going to be adding 10 percent Ethanol
10% ethanol will not be noticed
FUEL MAKES HORSEPOWER!!
I do not argue that fuel makes HP
All I wanted is that crisp snap of power out of a stock 450
x...you almost redeamed youself
Exactly my point, for 90% of the folks
My Kawasaki runs on diesel...
the only thing i dont like is the white ash...
i've seen this white ashy stuff too...
Who really needs race gas..
Switched up from the wanna-be class to the Premire then back again
Well me 450ty likes R-outlaw
I don't think it makes me any faster (or slower) than I already am but I just run Shell premium..
i remember the old SMC days
you old guys
your wrong...lead protects engine parts
oxygenated fuel is alot like adding alcohol to fuel
I would not run Av-gas
I visualize the kids scraping their heads and domes to sell of the resin for credits
Let's hear for(m) Ted
I was just trying to be cheap and
No I haven't tested the fuels I herd someone claim
Dave S, can you define fuel volitilty and how it makes power?
Dyno party at Secondis house!
BYOG - Bring-Your-Own-Gas????
I'd rather go to another jump party with EW thats for sure
oohhhhh yeah
Where in the HP curve is the 10%
all over!
My RMZ450 is 11.9:1 I thought it was lower than that
i've rebuilt rm-z450's and kx450f's that
I'm still more concerned about my filter leaking...
...ENOUGH TO PUT 110 IN A FOUR STROKE YOU DESERVE TO BLOW IT UP..you'll crack or break a piston in a few hours
People, people
..YOU CAN RUN 110 IN A FOUR STROKE ALL DAY LONG AND NEVER HURT IT
that is not correct. Gasoline has a certain amount of energy (heat)
An Old time mechanik once told me if I put mothballs in my gas tank my bike will go better
look close cuz they are small..

..End


Thanks to all you contributors for a most entertaining (smiles) discussion.

Me, all I want is a Subway and a thank you...maybe.

(grins)