Gas question - YZ 125

Dirtjump9 · #1 07-13-2005, 01:35 PM

Hi all!
Now that I have my new '05 YZ 125, I've been looking into the fuel aspect with more depth. The normal rating for "premium" around here is 93 octane with 10% ethanol content. I am planning to keep it on a strict diet of the "premium" with a 32:1 gas/premix ratio. I am a bit concerned about the ethanol content though. Will the 10% ethanol blend affect my engine?

Thanks for the help guys!

robertc · #2 07-13-2005, 08:52 PM

nope. my YZ has run premium for 2 years and it hasnt done anything. oh, and how did u get that sign thing in ur sig to display my ip and operating system? the isp isnt right tho

alex83 · #3 07-13-2005, 08:53 PM

Quote:

Originally Posted by robertc

nope. my YZ has run premium for 2 years and it hasnt done anything. oh, and how did u get that sign thing in ur sig to display my ip and operating system? the isp isnt right tho

I hope this helps but that's what I run in my CR125

Michael Parker · #4 07-13-2005, 10:46 PM

that is a very high ethonol content and i dont think that most people understand how bad ethonol is for a 2-stroke engine. do yourself a big favor and buy race fuel that is ethonol free. you engine will thank you and last longer. dont mix race gas because then you get the ethonol back.

pintlermotocros · #5 07-13-2005, 10:59 PM

So your sayin he should run 110 octane race gas 100% all of the time, with no mixture such as 50:50?? (50% race gas 50% premium)

I dont know if he can afford that. Most people cant, hell I cant. I think running 50 percent premium and 50 percent race gas is the way to go

: .

-Pintlar-

ShaneRider · #6 07-13-2005, 11:01 PM

Quote:

Originally Posted by pintlermotocros

I dont know if he can afford that. Most people cant, hell I cant. I think running 50 percent premium and 50 percent race gas is the way to go

: .

-Pintlar-

People I know that use race gas say there is almost no difference at all. 50 50 is a lot easier on the wallet.

pintlermotocros · #7 07-13-2005, 11:07 PM

Quote:

Originally Posted by ShaneRider

People I know that use race gas say there is almost no difference at all. 50 50 is a lot easier on the wallet.

50 50 is a lot easier on the wallet.

I have heard both "that it makes no difference" and that "it helps a lot" from different people. My dad and I are ordering some so I will let you all know how it is.

One thing I know for sure is that "it smells good!". One of the best parts of going to a pro supercross right there!

-Pintlar-

zuki · #8 07-13-2005, 11:25 PM

Normally race gas wont do anything for a stock motor. Sometimes you actually loose power.

KusoRaceR · #9 07-14-2005, 12:05 AM

Quote:

Originally Posted by pintlermotocros

50 50 is a lot easier on the wallet.

One thing I know for sure is that "it smells good!". One of the best parts of going to a pro supercross right there!

-Pintlar-

I can vouche for this quote!!! Smells damn good.

-KusoRaceR

Dirtjump9 · #10 07-14-2005, 12:31 AM

Thanks for the replies

Yea, I had a bad feeling about that when I read the sign on the pump and seen the ethanol content. We always go to this one gas station because they have some of the lowest prices of gas around here. And it seems as if gas prices increase by a nickel every week! I have a feeling that the oil company who refines their gas purposly increases the ethanol content to effectivly water down the gas, while still mantaining the octane rating.

I don't think I could ever afford race gas any time soon either....

I don't feel it's justified in my case, mainly because my bike is bone stock (no compression mods that would require race gas) and I won't be racing anytime soon. I guess I will have to look around for better quality gas... sigh

Faded · #11 07-14-2005, 11:22 AM

Quote:

Originally Posted by pintlermotocros

I have heard both "that it makes no difference" and that "it helps a lot" from different people. My dad and I are ordering some so I will let you all know how it is.

That's because some of the "race gas" being used it the right stuff, and sometimes it's the wrong stuff. Other times people seem to think that by just dumping it in the tank it will help while in reality it requires a jetting change to reap the benefits. Hopefully you got lucky and picked the right stuff.

The "race gas" term is a huge generalization...there are a variety of fuels on the market all with different properties and characteristics (besides octane rating) that should be taken into account before buying "race gas" for your application.

ossagp · #12 07-15-2005, 11:44 AM

I hear from some that ethanol is harmful you your engine. Ethanol in itself is not harmful. I have yet to have a seal problem from it. It will pick up moisture. It is one of the reasons that you shouldnt leave it for long without use. Check your chosen oil and make sure it mixes good if you are running premix. See that the oil doesnt settle out.

My biggest gripe about "corn" fuels is that there doesnt seem to be a whole lot of consistency in how much they put in the pump gas you get. I like oxygenated fuels, but when you don't know how much they are putting in it makes it hard to jet. We run into that each winter buying fuel for snowmachines. Get used to it though, because if you buy at the pump it is a coming thing.

Reuel · #13 07-15-2005, 02:48 PM

I run 110 leaded in all my 2 strokes, big and small. I buy it locally for $3.65/gal. Check around town with the guys doing the drag racing, they will have a good source for quality gas at a cheap price. The only difference I can honestly say is that my bike runs smoother, Does it make more power - don't know, dont care. Its runs smoother and i like the way it smells.

E-man811 · #14 07-18-2005, 12:32 PM

Dirtjump9,

You are on the right track here. Find a good quailty fuel that is readily available to you, select an oil, mix it at 32:1. Jet for this combination and use this as your fuel forever and always.

I would recommend something better than pump gas. There are many options.

* * * Opinion * * * Long post

"Most" people's SOTP (seat of the pants) Dyno will not notice a difference in power by just dumping face fuel in the bike.

For us, using race fuel has not been just about making more power. Yes, with engines that tightened up (compression) the race fuel starts to become necessary. The combination of the modifications and the correct fuel does make more power.

For the most part, the advantages of running race fuel even in a stock engine include:

- Consistency in tuning, the fuel is never a variable. Pump gas, who knows what you’re getting. The formula of additives and junk changes with different brands, different areas of country, different ages, different time of year, etc, etc, etc
- Leaded fuel brings added cooling to the combustion and added wear protection for all parts coated with fuel.
-Less additives means a cleaner combustion chamber throughout the life of the top end.
- Peace of mind

I know that stock engines are designed to tolerate pump fuels. I personally don't believe that that is what's best for them. None of my personal bikes has or will ever see pump gas, stock or modified. No VP C12... no ride.... That's just me.

VP Red can be had for much less than C12, Sunoco sells a good race gas from the pump at some race tracks.

Do some searching to see what's available in your area, then see which fuel would work best for you. Are there any race tracks like road courses, drag strips, circle tracks etc that might sell fuel? Are there any small shops near tracks that sell fuels, any race teams that may know where to buy fuels?

Bottom line, in most cases, any leaded race fuel will be better for your 2 stoke than a pump gas. Many can be found for $3-4 per gallon.

* * * warning * * * Controversial topic
Another option is to run AvGas, 100LL (low lead) specifically. Your local putput airport should sell it to you for about $3.50 per gallon.

We ran about a couple hundred gallons of this stuff through our 4 bike, stock engines, race team for 2 years of practice and racing every week. Nothing but spectacular results.

End opinion.

Ian

Reuel · #15 07-18-2005, 08:52 PM

Good point Ian. Pump gas is too unreliable. I gain a big piece of mind going to my favorite place down the road thats been there forever and buying the 110 leaded race gas they sell to all the local racers. Its repeatable quality and I never have to worry about what i am getting, its always exactly the same.

Michael Parker · #16 07-18-2005, 09:47 PM

you may not feel a difference but you engine will thank you for running race fuel with longer life and there is none of the little dirt particles in race fuel that are in pump fuel. trust me iv seen a guy run pump fuel through a special filter and there is all kinds of crap in there. not so with race fuel. Do you really want this running through you delicate engine

Faded · #17 07-19-2005, 04:28 PM

All "Race Gas" is not created equal. Why do you think there are so many types of gas available? Fuel type needs to be matched with its intended application otherwise it's like using 200 grit sand paper for butt wipe.

Vaporization of the fuel is key to more complete combustion, which is dependant on the volatility of the fuel. Fuel volatility is illustrated through a fuel's distillation curve. This information will show you at what temps various quantities of your particular fuel will vaporize. Instead of looking at octane numbers like everyone is so inclined to do you should be looking at volatility numbers unless detonation is a problem that you're trying to solve

In late model motocross specific bikes, both 2-stroke and 4, pump gas will not vaporize near as much as a motorcycle specific race fuel will. This is due to the higher distillation numbers (temps) that are required to vaporize pump gas. The length of the intake tracts on our bikes (i.e. short!) does not lend itself to heat build-up and retention making it hard to produce the required heat to better vaporize fuels with such high distillation numbers. By using a fuel that is properly match for its intended application you're able to more completely vaporize the fuel introduced to the engine. These gas vapors are what lend themselves to a complete, controlled combustion process unlike liquid gas. If your bike's fuel doesn't lend itself to more complete vaporization (pump gas) before spark is introduced then you're spitting raw fuel and horsepower out of your silencer.

A properly selected race fuel is never a "pour and go" either. Depending on the fuel, more often than not jetting changes are required to see the benefits. If you subscribe to the pour-and-go ideology then don't be suprised when the only difference you notice is your wallet getting thinner.

These are just a few (more) of the things to consider...

ossagp · #18 07-20-2005, 01:22 PM

WOW parker,,,I wonder how that pump gas with all that crud in it can run through an injected automobile!!!! There are plenty of reasons to run race gas,,,even where i come from auto gas is safe from a cleanliness aspect. Fuel in itself will not carry enough of anything to do measureable harm to the internals of an engine. (injection systems are a little different, and since you see them going 200,000 miles I am doubting your pump gas is not too bad). Anyone's air cleaner is going to pass more particals than you will get in your gas.

The sky hasn't fallen the last time I checked.

Michael Parker · #19 07-20-2005, 10:06 PM

Quote:

Originally Posted by ossagp

WOW parker,,,I wonder how that pump gas with all that crud in it can run through an injected automobile!!!! There are plenty of reasons to run race gas,,,even where i come from auto gas is safe from a cleanliness aspect. Fuel in itself will not carry enough of anything to do measureable harm to the internals of an engine. (injection systems are a little different, and since you see them going 200,000 miles I am doubting your pump gas is not too bad). Anyone's air cleaner is going to pass more particals than you will get in your gas.

The sky hasn't fallen the last time I checked.

Ill tell you why pump gas is okay for cars, because because on a car which is a fuel injected FOUR STROKE the gas does not pass by any critical bearings or seals as it does in a two stroke. the fuel is injected in, then burnt and pushed out on the exhaust stroke. the only critical part it hits is the valves the pistons and the rings. this is besides the fact that all the parts are a lot bigger and have higher tolerences that a purpose built high preformance two stroke dirt bike.

Kenny400 · #20 07-20-2005, 11:43 PM

Quote:

Originally Posted by Michael Parker

Ill tell you why pump gas is okay for cars, because because on a car which is a fuel injected FOUR STROKE the gas does not pass by any critical bearings or seals as it does in a two stroke. the fuel is injected in, then burnt and pushed out on the exhaust stroke. the only critical part it hits is the valves the pistons and the rings. this is besides the fact that all the parts are a lot bigger and have higher tolerences that a purpose built high preformance two stroke dirt bike.

Um, you obviously have no idea the size of the hole in a spray nozzle of an automotive fuel injector. If pump gas was as dirty as you make it sound, the fuel injectors would stop up in no time flat.

So everyone who's using pump gas is just asking for excessive wear and tear on their smoker motor huh?

: THATS ALOT of people. Dirt is one of the words in dirtbike. If they were that sensitive to a little dirt they wouldn't last very long. Unless you get an underground tank that is leaking water and dirt/mud into the fuel, the cleanliness of pump gas should be fine.