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lazierhobo

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I just finished rebuilding my engine, and i cant seem to find any high octane gas.

i have a cool head with 19 cc domes, and the engine is bored 60 over.

 

the only thing i can find is AvGas, which is aviation gas, it is 100 octane and low lead, meaning 2 grams per gallon.

 

has anyone heard of running this? or see any problems?

or does anyone know where i could find high octane gas in the upstate NY area.

 

also i know that compression is just on the line of needing race gas, what has anyones experience with octane booster been? i really really hate using additives, but its killing me having this finished quad, and not being able to start her up.

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I just finished rebuilding my engine, and i cant seem to find any high octane gas.

i have a cool head with 19 cc domes, and the engine is bored 60 over.

 

the only thing i can find is AvGas, which is aviation gas, it is 100 octane and low lead, meaning 2 grams per gallon.

 

has anyone heard of running this? or see any problems?

or does anyone know where i could find high octane gas in the upstate NY area.

 

also i know that compression is just on the line of needing race gas, what has anyones experience with octane booster been? i really really hate using additives, but its killing me having this finished quad, and not being able to start her up.

 

There probably isn't a ral problem with running AV gas blended with regular gas. I would reccomend going to one of the racing fuel manufacturers web sites and using their dealer locator feature to see if there are any dealers around you. Sunoco, VP, Trick , would all be good starting places to look. If all else fails, wander down to your local cycle shop and ask the folks that work there. They ought to know where to get it. they may even be able to get it for you. :thumbsup:

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Pump gas, race gas or propane?

 

Without discussion or announcement, gas stations across the country have begun cheating motocross racers out of one octane. Since your owner's manual calls for a minimum of 92 octane gasoline-and the oil companies have started to reduce the standard-issue fare to 91 octane-many riders may be tempted to switch to race gas.

 

Not every gas pump has made the one octane reduction, but they will. Gasoline is the blood of your engine. It needs it. And you want to have the best possible gas (at the best possible price). Read on to get the full skinny on the secret world of gasoline

 

 

 

QUESTION ONE:

WHAT IS OCTANE?

 

 

A hydrocarbon chemical that burns very easily and is found in petroleum. Of all the chemicals used to formulate gasoline, octane is the most explosive one that can still handle lots of compression and heat without spontaneously igniting.

 

 

 

QUESTION TWO: WHAT IS

SPONTANEOUS IGNITION?

 

 

 

Spontaneous ignition can also be called knocking, pinging, detonation, pre-ignition or the death rattle. If a cylinder has too much compression, bad ignition timing or excessive heat, it is possible for the gasoline to ignite at the wrong time or place. This misfire creates undue combustion pressure and heat inside the cylinder. Sustained spontaneous ignition can result in top-end damage and seizure.

Since the internal combustion engine was first popularized in 1912, engine tuners have played a game of Russian roulette with death rattle. Why? The most power can be found with the combination of razor-edge ignition timing, abundant fuel and maximum heat. The margin of error is small.

 

 

 

QUESTION THREE: HOW CAN I TELL IF MY BIKE IS PINGING?

 

 

 

To the untrained ear, pre-ignition is difficult to hear. It's almost impossible to detect on a 125 or four-stroke, sometimes difficult on a 250 and easiest on an Open class two-stroke. If the engine detonates, it will knock at full throttle, mid rpm and under a load (hill, mud or a wheel full of banners). If you hear a metallic crackling sound, your bike is detonating.

 

Sometimes you can feel it more than hear it. Under a load, the bike will run flat and almost feel like it's starting to seize. A spectator might hear it (even if you don't), so have your mechanic listen for the tell-tale death rattle. Of course, a tuner can see signs of detonation when he takes your blown engine apart to replace the piston-but then it's too late.

 

 

 

QUESTION FOUR: CAN I SEE IT

ON A SPARK PLUG?

 

 

 

Sometimes, but not always. A severe case of detonation will chip or crack the porcelain and erode the plug gap edges. Even if the bike feels like it is running right, but the condition of a fresh plug is suspicious, you might not have enough octane.

 

 

 

QUESTION FIVE: WHAT CAN I DO IF I HEAR THE RATTLE?

 

 

 

First, re-jet! Detonation is often the result of being too lean. If a bigger main or higher clip position improves how your bike runs, then you have fixed the problem. If the bike runs too rich or the pinging doesn't subside, consider race gas.

Race gas, as a rule, is for high performance racing engines, not a box stock mill straight off the showroom floor.

 

 

 

QUESTION SIX: HOW IS OCTANE MEASURED?

 

 

 

In 1928 the Cooperative Fuel Research Committee developed a detonation testing machine. Their single cylinder, valve-in-head, watercooled, 612cc test engine had variable compression. While running at 600 rpm, the engineers gradually increased compression until a knock indicator sensed detonation. The highest compression value that resists detonation is assigned a number. It is referred to as the Research Octane Number (RON).

 

Unfortunately, the 1912 test device was not accurate enough for modern engines. Or rather, the gasolines with high RON numbers weren't suitable for high-load, high-rpm use. So, a new test machine was devised. Similar in makeup to the RON unit, this one ran at 900 rpm, but incorporated variable ignition advance. With the new testing device, gasoline could be tested under a load that was similar to the severe, sustained high-speed and high-load conditions of modern engines.

 

The rating from this machine is called a Motor Octane Number (MON) and it is always lower than the RON.

 

 

 

QUESTION SEVEN: WHAT IS RON+MON/2?

 

 

RON+MON/2 is the anti-knock index number that is listed on the pump at your friendly local service station. It is derived by adding the RON figure to the MON and then dividing the sum by two. The difference between those two numbers indicates the fuel's sensitivity to detonation.

 

 

 

QUESTION EIGHT: WHICH OCTANE NUMBER SHOULD I BELIEVE?

 

 

 

While the MON is the only octane count of any real value, gas stations don't post it. All you are given is the anti-knock index number. That could be misleading. A gas with a lower MON and a higher RON could have the same index number as a gas with a lower RON and a higher MON. The numbers don't always jive with the desired result.

What you want is the highest possible MON, but the oil companies don't tell you that. The only way you can judge is by how your bike runs.

 

If you are buying race gas, always ask for the Motor Octane Number (MON).

 

 

 

QUESTION NINE: HOW MUCH OCTANE DOES PREMIUM UNLEADED HAVE?

 

 

 

That depends. In most states it's 92-octane. But, California has recently switched to 91-octane. In remote, low pollution areas, it's still possible to find 93-octane premium unleaded. If you live in Colorado (or at 10,000 feet) the best pump gas at the local station will only be 87-octane unleaded (engines require less octane at high elevations).

 

 

 

QUESTION TEN: WILL MY BIKE RUN BETTER WITH MORE OCTANE?

 

 

 

No! Not if it runs correctly on pump gas. If an engine can be ridden under a race load without detonating-even with 91-octane unleaded premium-you seldom find hidden power in $6-a-gallon race gas. Octane alone doesn't dictate how much horsepower an engine makes-and more octane does not equate to more power (in fact, sometimes the equation runs the other way).

 

 

 

QUESTION 11: WHAT ARE OXYGENATES?

 

 

 

Oxygenates are chemicals that contain oxygen, have a good anti-knock value and reduce the smogforming tendencies of exhaust gases. Oxygenates replace most of the aromatics previously used to boost octane in unleaded fuels. The EPA mandates that oxygenated fuel be used in major metropolitan areas. Cities that lie in these areas are labeled "Reformulated Gas Cities." Some of these Reformulated Gas Cities are only required to sell oxygenated fuel during the summer or when air quality is at its worst. But some, like Los Angeles, pump oxygenated fuel year round.

 

Methyl tertiary butyl ether (MTBE) and ethanol are the two most common oxygenates. Ether is the active oxygenate in MTBE and corn alcohol is the active oxygenate in ethanol.

The downside of the oxygenate MTBE is that it might contaminate municipal water supplies. When ether mixes into water, it's very difficult to remove. Environmentalists want MTBE eliminated, but since the oil companies have yet to find a replacement oxygenate that has the same octane value as MTBE, the octane value of gasoline in high-density areas has lost an octane because of the reduction in MTBE.

 

 

 

QUESTION 12: WHAT ABOUT ETHANOL?

 

 

 

Ethanol is used in the corn growing states of the Midwest. The rest of the country gets MTBE because the oil companies only use ethanol where corn is readily available. The greatest expense in the gas business is the transportation and storage of gasoline. No one would pay the price to transport ethanol to California.

 

 

 

QUESTION 13: WHAT ARE THE PROBLEMS WITH ETHANOL?

 

 

 

Ethanol, like alcohol and brake fluid, is hydroscopic. That means it absorbs moisture. Since oil floats on water, there is a concern that moisture could cause the premix oil to separate in the gas. It's mostly a non-issue though, because ethanol is sold during the drier summer months. Plus, vigorous shaking before pouring, and agitation over whoops, doubles and triples keeps, the premix in a solution.

 

The quality of ethanol is also an issue. Each time ethanol is moved from one location to the next, it is opened and exposed to the atmosphere. If you get an old supply of ethanol, moisture contamination could have turned it into a cheap, lower octane gas. But, it will still be pumped into your gas can from a premium handle and at a premium price.

 

 

 

QUESTION 14: WHAT ARE

WINTER AND SUMMER GAS?

 

 

 

Oil refineries alter the fuel mixture to accommodate the weather. The winter blend is formulated for easier starting in colder temperatures. Winter gas has been known to boil in the carb line and create enough vapor lock to keep the engine from running right.

 

In the summer, the gas mixture is reformulated for warmer climes and mostly to ease smog concerns. In the Reformulated Gas Cities, especially Los Angeles, gas stations sell summer gas year round.

 

 

 

QUESTION 15: ARE PUMP

GASOLINES DIFFERENT?

 

 

 

You bet. Each oil company has their exclusive mix of octane enhancers, antioxidants, metal deactivators, deposit modifiers, surfactants, anti-icers, corrosion inhibitors and dyes.

It gets better yet. Just because you buy Chevron doesn't necessarily mean that what you're pumping was originally destined to be sold under a striped Chevron banner. If Hee-Haw Gas next door is going out of business, who knows where their underground supply of reduced-price gas will end up?

 

 

 

QUESTION 16: WHO SELLS

THE BEST PUMP GAS?

 

 

 

You never know, but there are a few precautions you can take to increase your odds of getting good gas. (1) Buy fuel from a name-brand station. (2) Choose a station in a high-use area and one that sees frequent business. The more gasoline the station sells, the fresher the supply will be. (3) Avoid stations that look like they were once used as a set for "Return To the Thunderdome." If the station is clean, chances are they have the same attitude towards fuel handling and

storage.

 

 

 

QUESTION 17: WHEN SHOULD

I USE RACE GAS?

 

 

 

This is the $6-a-gallon question. There are five reasons you might need to run race gas: (1) If your engine has been modified with more ignition and compression, it will likely need more octane. (2) If you experience detonation with the best available premium unleaded. (3) If the consistency and quality of local pump fuel is questionable. (4) Some bike brands take to race gas better than others and, when re-jetted, produce more horsepower. (5) You're too cool and like to spend money.

 

 

 

QUESTION 18: ARE RACE

GASES DIFFERENT?

 

 

 

Not all race gases are a smart buy. Pro Circuit sells $5.75-a-gallon, 108-octane VP C-12, but races with $11-a-gallon, 106-octane VP MR-2. Why? Although lower in octane, MR-2 has a higher energy value and can potentially make more horsepower in a carefully tuned race engine. Some of the factory teams use $15-a-gallon

MR-1, which has a higher energy value yet, but a lower octane of 95.

 

 

 

QUESTION 19: IS LEADED

BETTER THAN UNLEADED?

 

 

 

As long as the octane is sufficient, motorcycle engines don't know the difference between leaded and unleaded gas. Lead is the easiest and most economical way to raise octane during the fuel formulization process. That is why the race gas you purchase will generally be of the leaded variety. Four-stroke engines designed before the advent of unleaded gasoline used lead to lubricate the valve seats.

 

 

 

QUESTION 20: WILL LEADED FUEL MAKE MY VALVES LAST LONGER?

 

 

 

Current four-strokes use a different material in the valves and a special seat that is designed to run on unleaded gas. Technology has moved forward and lead is no longer needed to cushion the valves on a YZ-F.

 

 

 

QUESTION 21: DO FOUR-STROKES NEED MORE OCTANE?

 

 

 

Two-strokes stand to benefit more from higher octane fuel than four-strokes. The design of a two-stroke's pipe keeps more heat backed up against the cylinder and creates the potential for hot spots that could lead to detonation.

 

 

 

QUESTION 22: CAN MY STOCK BIKE BENEFIT FROM RACE GAS?

 

 

 

Compared to pump gas, the quality of race gas will always be closer to what it's claimed to be. Running race gas allows for the potential to jet leaner for more, crisper, cleaner-hitting power. But there are no absolutes here. The bike you are riding will run the best with the octane it is tuned to use. If you run race gas in an engine that's tuned for pump gas, it can actually hurt performance.

 

 

 

QUESTION 23: CAN I MIX RACE GAS WITH PUMP GAS?

 

 

 

Yes. Lots of riders do it to save money. But don't think of it as improving the quality of pump gas, it's more like diluting the quality of the race gas. It does work, though, and many riders run a 50-50 mix of 92-octane pump gas and 100-octane race gas. The main caveat still remains, however: if your engine doesn't need race gas, it probably doesn't need a half-half mix either. Unless you have an unusual octane requirement and are on a tight budget, it's best to run pure race gas or pure pump gas.

 

 

 

QUESTION 24: WHAT ABOUT OCTANE BOOSTERS?

 

 

 

Most octane boosters contain toluene. Like MTBE, any component that is strong enough to boost octane is harsh enough to harden seals and turn plastic gas tanks yellow. The quality of the end product is only as good as the gas you mix it with. Octane boosters are a Band-Aid fix for when race gas is not available (and the local supply of gasoline is questionable). The worse the gas, the more you will benefit from octane boosters.

 

 

 

QUESTION 25: WHAT ABOUT AVGAS?

 

 

 

Aviation fuel is controlled by a different agency and follows a different octane scale. Additives for altitude and temperature are also included, some of which are not compatible with premix oil. Unless you're thinking of jumping the Snake River on a rocket bike, avoid avgas.

 

 

 

QUESTION 26: HOW FRESH SHOULD MY GAS BE?

 

 

 

If you use a plastic container, choose one with a darker color. Dark cans block out UV light better than white ones. Keep the gas in the shade and at a consistent temperature. Avoid wild swings in temperature that could make the fuel susceptible to evaporation and condensation.

 

It's best to use gas as soon as it is mixed and to keep the freshest supply on hand. As soon as you pour the fuel, immediately seal both tank's gas caps. If you ride every week and consistently run fuel through the bike's tank as well as the gas can, there is little concern of fuel breakdown.

 

 

 

QUESTION 27: HOW SHOULD I STORE MY FUEL?

 

 

 

Steel gas cans are better than plastic. Don't store fuel in a plastic gas tank or plastic gas can for longer than three weeks. If stored for extended periods in a plastic can the gases will evaporate through the porous plastic. You end up with a denser fuel that will effect jetting. Two months is the limit for gas in a steel can.

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thanks for the help

 

ive called all the local places, and when you ask for race gas they act all confused and kind of laugh at you for even asking.

 

i know of a few places to get race gas but they are all way far away, and none provide the 24/7 service of an airport.

 

 

Sorry if im bling but what is your copression?

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thanks for the help

 

ive called all the local places, and when you ask for race gas they act all confused and kind of laugh at you for even asking.

 

i know of a few places to get race gas but they are all way far away, and none provide the 24/7 service of an airport.

 

 

Sorry if im bling but what is your copression?

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Short version, its perfectly fine for your banshee, and its cheaper than race gas. It is lower octane than most race gas (although much higher than pump gas), so make sure you know your fuel needs.

 

Here's my $.02 on AV gas: There are several different kinds of AV gas and you need to know a bit about them before choosing what fuel you buy. For instance you can get an octane rating that is in the 110 rang via the (r+m)/2 method. However, if you are not aware of what you are buying you may wind up with a fuel that is similair to kerosene or you may wind up with something that is more like diesel fuel.

 

Now, if you have armed yourself with the proper information you may find an unleaded gasoline type fuel that can range for 100 to 120 octane. However this fuel is derived from a different hydrocarbon structure and will probably contain additives that lower the surface tension of the fuel which prevents foaming and the trapping of air bubbles. This fuel is probably ok to run, but it is relatively the same price as an economy grade of race fuel. Afterall this you must know that the reason for the higher octane rating is to help stop the engine from detonating at altitude. It is not because piston driven airplane engines are very high compression, though as far as the engine is concerned, the results are the same.

 

Two wrap up my rant..........your engine will make the most power when it has the most combustable fuel mixture in it cylinders. That means that you ought to run the lowest possible octane fuel that can be run without detonating. There are alot of people out there that swear by it, but I am not one of them. If I had no other choice, then i might consider it, but I have always been able to find race gas. :thumbsup:

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Two wrap up my rant..........your engine will make the most power when it has the most combustable fuel mixture in it cylinders. That means that you ought to run the lowest possible octane fuel that can be run without detonating. There are alot of people out there that swear by it, but I am not one of them. If I had no other choice, then i might consider it, but I have always been able to find race gas.

 

I agree 100%

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Here's my $.02 on AV gas: There are several different kinds of AV gas and you need to know a bit about them before choosing what fuel you buy. For instance you can get an octane rating that is in the 110 rang via the (r+m)/2 method. However, if you are not aware of what you are buying you may wind up with a fuel that is similair to kerosene or you may wind up with something that is more like diesel fuel.

 

Now, if you have armed yourself with the proper information you may find an unleaded gasoline type fuel that can range for 100 to 120 octane. However this fuel is derived from a different hydrocarbon structure and will probably contain additives that lower the surface tension of the fuel which prevents foaming and the trapping of air bubbles. This fuel is probably ok to run, but it is relatively the same price as an economy grade of race fuel. Afterall this you must know that the reason for the higher octane rating is to help stop the engine from detonating at altitude. It is not because piston driven airplane engines are very high compression, though as far as the engine is concerned, the results are the same.

 

Two wrap up my rant..........your engine will make the most power when it has the most combustable fuel mixture in it cylinders. That means that you ought to run the lowest possible octane fuel that can be run without detonating. There are alot of people out there that swear by it, but I am not one of them. If I had no other choice, then i might consider it, but I have always been able to find race gas. :thumbsup:

100LL is what I buy, and from what I've found, there aren't different types (brands sure, but they are all 100LL). Jet A is the kerosene. And while it is cheaper, no I don't think the shee needs jet fuel. :biggrin:

 

I've done my homework on this. So far I have not yet come across one single fact that shows AV gas to be a bad choice. All these "additives" people say are put in the gas, nobody ever knows what they are when you ask them. They just know that its been put in the gas, and "its bad cuz its for dem aeroplanes".

 

As far as the big long post up there that says AV gas not compatible with premix, wrong. 100LL will mix fine with pre mix.

 

This will be a debate till the end of time, but like was mentioned, there is no point in using more octane than you need. I don't need anything more than 100 octane, and 100LL is cheaper than anything else thats comparable.

Edited by dawarriorman
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