Hawk 250cc fuel type?

[franque]

If it's pinging (US term, pinking is UK + Commonwealth), it's probably running too lean, have you rejetted it?

Also, E3 plugs are a scam, and if you think running premium in a 9:1 air-cooled motor is a good idea, or even makes a whit of difference in mpg, in particular an improvement in consumption, I've got a bridge for sale.

If you look at what octane ratings mean, you've actually got less BTUs per fixed volume with higher octane gas, so unless we're talking about a car with a knock sensor that pulls so much timing that it needs aggressive application of the throttle for normal use, there's virtually no difference, with maybe a slight edge to lower octane fuel, in fuel consumption. In that scenario, you would only see a difference if the engine had enough load on it to be at or near WOT and spending more time there due to the loss of power. Otherwise it's purely psychological, especially in a carbureted TBR7.

[JFOlivier]

Franque not so sure about the BTU's of premium as against regular gas, also in Africa there were only 2 grades, 93 which was regular and 97 which was premium, not sure how you get your octane grades here but a special engine that measured the Knock ratio was used by Shell and was used for blending to a particular octane rating. Most distilled gasoline ends up at around 85 octane whereas a cut of octane itself would be at 100 octane. Most kerrosene, Jet A1 and other high end fuels are reformed from straight chain to to aromatic chains thereby increasing their octane rating. Here there are 3 grades so I would take a look at the mid grade and see if there was a decrease in the pinging, can't change the jets on the X-pect, dont know what the compression ratio of the engine is and can't adjust the ignition timing either so whats to lose trying mid grade.

[HiveGuys]

Post comment edit:
franque, I didn't want this to get personal. I agree with you: every petro-scientist and gasologist in the world says if your engine isn't designed for premium, there is no benefit. If it ain't knocking with regular, you're wasting your money on higher octane -- "don't try it 'til you knock it" came to mind and made me chuckle. I understand the energy density between fuel grades is likely the same, and the higher octane is right for higher compression, modern ECU controlled engines to prevent improperly timed ignition.

Since about 1980 I've tried different grades in different rigs and have concluded that performance has been better with higher octane in all but one -- sometimes more noticeable than others, or in the case of mpg, more miles recorded (1-5 mpg) than other times.

The one engine that was different was a 95 Virago 1100 v-twin; it hated premium (at least the one I tried), it bucked and kicked until all the premium was pushed through with regular.

I stand by the post below, and encourage anyone to "don't knock it 'til you try it" with the premium (should be at least three tanks-worth for a proper test). Admittedly I haven't run regular through the TBR7 yet because my cans all contained premium, and I just recently got the bikes plated, so now I'll likely fill them at the pump and test regular against premium.
Cheers!
Original post:
Not going to debate or disagree with you franque -- only going to report on results. I'll see that bridge, and raise you on mpg's.

92 GMC 4.3
94 F150 5.0
95 Chevy 5.7
08 Kia 3.8
10 RAV4 2.5
12 Elantra 2.?
08 V-Star 1300
(and other vehicles in the past)

ALL get better, documented mileage to the point that the extra $ per gallon pays to run premium. And as much as I refrain from operating on "feelings", they all "feel" like they have a bit more giddy-up.

I may be translating this to "more power" in a somewhat unscientific manner, but there it is.
If the higher octane means a higher tolerance to pre, post, or "improperly timed" fuel ignition, then that itself might force a better, more properly timed ignition -- hence efficiency, and hence the possibility of more power. (also, see "PowerNation's" documented dyno use of higher octane delivering more hp and torque).

As in ballistics, I recommend people use testing to see what "ammo/fuel" works best in their own machine. Results WILL vary.

The reason I use premium in all my IC machines is because that's what I bring home in cans for the bikes; I might be spending more than necessary on tools like chainsaws and leaf blowers, but everyone in my garage is happy.

Jury is still out on the E3, you may be right. Or not; test a new, properly gapped plug against a worn/fouled/improperly gapped plug -- plugs are influential. You may be correct about the E3 being a gimmick, but it stays for now, I'm still testing.

All the best, when in doubt - test.

[BikerBen]

I completely agree with hiveguys, I try to run the premium fuel in the non ethanol, if you can find it where you live

[Zapkin]

I apologize if this sounds repetitive, but it's essential to keep in mind that when we're adding such a small amount to our fuel tanks, we're essentially getting what's already in the hose, correct? I wonder if there might be a valve or some other solution for this. Anyway, I typically use lower-priced fuel, or when I'm in Cameron, they offer 90-octane ethanol-free fuel. The only challenge there is dealing with their intolerance. they seem anti-non white dude. to be honest. will probably never go back. BUT was a great place back in the day.

[Thumper]

Detonation, or ping is rough on a piston/cylinder/rodbearings. It is caused by fast combustion. Google detonation. Higher octane gas used to contain lead which slowed down the combustion. Now they contain slower burning hydrocarbons which also increase octane.

Ethanol also slows down the burning but does not increase octane, so ethanol actually is good for an engine if the plumbing can handle EtOH. But ethanol containing fuels burn less efficiently (already partially oxidized).

Keep in mind that you are getting 70mpg or more. Spending an extra $1 to tank up (2 gallons or so) is not much. To me worth the money. No reason to subject the engine to ping. I buy midrange or high octane for my ZS172-FMM, WITH ethanol.

[Texas Pete]

Almost got it. Ethanol does have some unique properties when used as a fuel additive. Ethanol can slow down the burning rate of gasoline, which can be beneficial for engine performance in certain situations. This slower combustion can help reduce engine knock or detonation, which is especially important in high-performance or high-compression engines. Not in low-compression iron-headed air-cooled glorified lawn mower engines on most of our single-cylinder Chinese motorcycles.

However, ethanol itself does not increase the octane rating of gasoline. In fact, ethanol has an octane rating of around 113, which is higher than most gasoline, but it doesn't directly boost the octane rating of the entire fuel blend when mixed with gasoline. Instead, ethanol's ability to reduce knock is due to its cooling effect on the intake air and its slower burn rate.

While ethanol can be beneficial for engine performance, it's important to note that ethanol-containing fuels may result in reduced fuel efficiency in some cases. This is because ethanol has a lower energy density compared to gasoline, so you may need to burn more ethanol-blended fuel to achieve the same mileage as pure gasoline.

Additionally, the use of ethanol in engines does have some potential downsides, including increased fuel system corrosion in older engines not designed for ethanol, potential vapor lock issues in hot weather, and concerns related to the environmental impact of ethanol production. It also can lead to fuel turning to jelly rapidly when a bike is left for a period of time with fuel still remaining in the float bowl.

As a counterpoint example. I only use USA 87 octane ethanol fuel in my engine. To also answer Zapkins about fuel in the hose to the pump nozzle yes you do get less than a gallons worth of fuel depending on how much the hose can hold volume wise. On shared pumps with selectable Octane rating buttons I have gotten high octane fuel mixed in with the 87 I was pumping. This is directly visible on my spark plug as octane booster combustion deposits. As I don’t know how long it will be until my next ride I always turn my pet cock closed at the end of the ride while the engine is running and let it drain the carb bowl below the ability of the jets to pick up fuel at which point the engine quits running. Then I shut off the bike until next ride.

[Thumper]

Regarding "good" fuel in the hose... Follow the Cobra, or Corvette on the pump

Or fill your 2.5 gallon can with ethanol free high test (or fill your bike!), then move the nozzle to your turbo charged 4 cylinder car, and switch to midgrade. Get some boost
Either way, you paid for it!

[Boatguy]

Regarding the fuel in the hose, I had a friend at a job I had between high school and college.

He had some kind of moped he used to get to work. One day he couldn’t get to the place we both worked at because he ran out of money and gas.

He pushed the moped to a big gas station and shook out what he could from the hoses without buying any gas.

It was enough to start the moped and get him to work! (It wasn’t too far and it was payday- cash)

True story

[XLsior]

In Australia we have individual hoses for each fuel type per bowser fill up station, But I believe In the US you have 1 hose with selectable fuel type...Depending on how small you motorcycle gas tank is...you're pretty much filling up on what the last guy had selected.

So you might as well just go with the cheapest and hope for free splash or 2 of free premium.

[Boatguy]

I feel like the real answer to the question in the title of the thread, “Hawk 250cc fuel type?” Is the same for all China bikes and the answer is:

Anything but diesel and kerosene. Lol

[Megadan]

Originally Posted by XLsior

In Australia we have individual hoses for each fuel type per bowser fill up station, But I believe In the US you have 1 hose with selectable fuel type...Depending on how small you motorcycle gas tank is...you're pretty much filling up on what the last guy had selected.

So you might as well just go with the cheapest and hope for free splash or 2 of free premium.

Most pumps tend to be single hose here, yes. The difference is in the design of the pump and hose system. Not all of them actually retain alot of fuel, with most modern systems having a high meter with a drain-back system. Even a low meter system tends to have a drain-back on it and the "lost" volume that drains off is compensated for in the calibration of the pumps since it is an easily known volume. At most you might get a few fluid ounces of whatever the last guy had in the hose itself. Older pump systems may retain a bit more, but we are still talking a few ounces.

In reality, even in a couple of gallons, a few ounces of a different octane isn't enough to make any meaningful difference. A U.S. Gallon is 128 ounces, for reference sake.

My Honda is a high compression high specific output engine with an ECU tune on it meant for 91-93 (R+M)/2 octane rated fuel (95-98 in your terms). I have never had a single issue with filling it up at any fuel station. I have experienced what that engine behaves like with bad fuel too so believe me when I say... I would notice lol.