Fuel octane?

[liverchip]

What's major consensus as to the octane requirement on these bikes? I'm running regular 87 here.

[blimpman]

Since it is only 2 gallons at a time... I use 90 or above.

[dlunt]

If your engine isn't pinging on the lower grade stuff, 98% (guestimate) of the time it won't run any better on higher octane fuel.
Most engines will run fine on the 87.
BUT, having said that keep this in mind.
If you have the OHV engine you may not hear or feel the pinging because the engine makes a lot of noise and vibrates a lot even when running correctly.
I went ahead and tried the higher grade in my Lifan and it really does run better. 89 octane.
Experiment and see what you think.

[pumpkin]

i got my 2006 gy-5 at a dealer and the service man said to use 93 octane or higher,but if it will do fine on 87 i'll save $$ at the pump

[Roketarider]

I use 92 or 93...its only like 6 bucks to fill the thing up...

[bfe71730]

I can tell a big difference on mine, I've started using the 93 octane, not only does it run better, but an ATV mechanic told me that air cooled engines run cooler on super unleaded.

[mdsuave13]

Originally Posted by bfe71730

I can tell a big difference on mine, I've started using the 93 octane, not only does it run better, but an ATV mechanic told me that air cooled engines run cooler on super unleaded.

i agree

[sheadouglas]

I absolutely agree on the higher 92 or 93 octane. I put a tank of gas a week in my bike, and early on I tried the cheap stuff. You really can tell a difference in the way the bike performs.

[bfe71730]

Originally Posted by sheadouglas

I absolutely agree on the higher 92 or 93 octane. I put a tank of gas a week in my bike, and early on I tried the cheap stuff. You really can tell a difference in the way the bike performs.

yeah, these little thumpers need all the help they can get.

[ambassador]

I use 93 in my bike but as far as my research goes, the lower the octane, the bigger the bang... Apparently it takes less spark to ignite a lower grade than it does a higher grade, what does this mean in the 200cc world??? As well as my change in oil, I'm gonna run a gallon of 89 through my tank and keep ya'll updated...Bike runs fine on 93 though...

[ob1]

I run premium in all my bikes.

I have seen what pinging can do to a piston and combustion chamber. Pinging causes pitting and erosion, especially in the situations enduro racing can bring; high operating temperatures and low airspeed across the fins. Casual trail riding can do the same thing.

It costs, what, 50 cents more per tank?

[SamM]

One thing that many people may not be aware of is that the US and a few other countries uses a different index to rate octane. This index is called the Research Octane Number (RON). This is the number shown on the gas pump where you purchase your fuel. It's best to check the RON that the manufacturing country uses. This number usually varies a good bit on the US pumps. I'm not sure what RON or which standard they use in China. Since the British were in Hong Kong for many years, my guess would be they use the European standard RON. The pumps in the US show a 4 to 5 lower numerical difference for the same fuel compared to the European RON index. If your owners manual says 92 then you should easily be able to run US 87 in your bike, because of the difference. Of course, this is only IF the Chinese use the European standard. It's interesting to me that service techs are suggesting, "93 octane or higher." Where do you find fuel higher than 93. We have a few station in my area that carry 93, 94 and maybe a 95. Most are at 92. My guess would be that the owners manual states 93 octane and they don't know of the different ratings. Since they see 93 in the manual they are blindly recommending it.

One of my bikes is a european adventure bike. This bike can use either the higher octane fuels (European 93 RON is recommended) or the lower octane fuels that are available in third world countries. I have done this in my bike and have had no problems at all! You just unplug a connection under the seat to change the ignition curve. My plan is to add a switch in the glovebox and mark it Low and High to make switching between fuels easier. Actually, it will just be more convienent. I always use the higher octane because I can. To me it's cheap insurance for an expensive bike! I have also used 89 US octane fuel without unplugging the connector and the bike has been just fine.

Here's a link: http://en.wikipedia.org/wiki/Octane_rating

Here is a short explanation of the differences. Basically, the same information that I posted above. You can read more in the above link.

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2.

I thought this might help!

[SamM]

The power output of an engine depends on the energy content of its fuel, and this bears no simple relationship to the octane rating. A common myth amongst petrol consumers is that adding a higher octane fuel to a vehicle's engine will increase its performance and/or lessen its fuel consumption; this is false—engines perform best when using fuel with the octane rating they were designed for and any increase in performance by using a fuel with a different octane rating is minimal or even imaginary.

Using high octane fuel for an engine makes a difference when the engine is producing its maximum power. This will occur when the intake manifold has no air restriction and is running at minimum vacuum. Depending on the engine design, this particular circumstance can be anywhere along the RPM range, but is usually easy to pin-point if you can examine a print-out of the power-output (torque values) of an engine. On a typical high-rev'ving motorcycle engine, for example, the maximum power occurs at a point where the movements of the intake and exhaust valves are timed in such a way to maximize the compression loading of the cylinder; although the cylinder is already rising at the time the intake valve closes, the forward speed of the charge coming into the cylinder is high enough to continue to load the air-fuel mixture in.

When this occurs, if a fuel with below recommended octane is used, then the engine will knock. Modern engines have anti-knock provisions built into the control systems and this is usually achieved by dynamically de-tuning the engine while under load by increasing the fuel-air mixture and retarding the spark. An engine that might require 93 octane at sea level may perform at maximum on a fuel rated at 91 octane if the elevation is over, say, 1000 feet.

[SamM]

I'm not sure if these bikes have a knock sensor built into them. My guess would be no!

[fatboy250]

SamM,
Thanks for the info. I wasn't really gonna say much on this thread, but since you have the data. I have run 87 in mine since day one. Dad has run 93 since day one. I can't tell any real difference between the two, but Dad insists that his runs better....yada...yada...yada. But he's that way with all his vehicles. Old habits die hard.