Topic: High octane fuels & the 750

[Justin]

Curious to know what octanes you lot use for aggressive street machines as well as track days. I just found a petrol station near me that sells ethanol free fuel if I buy 96, 98, or 101 octane.

My k0 is factory and I don't know how it'll respond to high octane. Maybe you have some insight?

My k1 is still being built but will be an 836cc performance oriented machine. Could I run the higher octane fuel or should I suck it up and live with the standard 91 octane ethanol mix?

Currently living in California


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[Sam Green Racing]

No problem Justin, I ran race fuel in mine with no problems, as long as you flush it out before storage.
Oxygenated fuel can turn valves and seats rusty if not flushed out.

Sam.

[turboguzzi]

not much use in higher octanes if you are not increasing compression ratio. higher octane doesnt mean higher enrgy, just more detonation resistance that lets you run higher CR, and thats where the extra power comes from.
complex subject, i'd say 11:1 is ok with 98 but what if you need to refuel in some other place that doesnt have it?

[seanbarney41]

also...if you have changed jetting to run correct with 10 percent ethanol, you might run just a little rich with no ethanol

[Retro Rocket]

not much use in higher octanes if you are not increasing compression ratio. higher octane doesnt mean higher enrgy, just more detonation resistance that lets you run higher CR, and thats where the extra power comes from.
complex subject, i'd say 11:1 is ok with 98 but what if you need to refuel in some other place that doesnt have it?

Bingo...

[goldarrow]

I normally run 87, on one summer I switched to 91 for several tanks, and honestly could not tell the difference, but then again my bikes are stockers no engine mods

[SOHC4 Cafe Racer Fan]

No problem Justin, I ran race fuel in mine with no problems, as long as you flush it out before storage.
Oxygenated fuel can turn valves and seats rusty if not flushed out.

Sam.

Good to know, Sam.  I thought ethanol-free race gas was okay to keep in the tank, especially compared to ethanol-based fuels getting gummy with non-use.

[Tintop]

As TG said, unless your running over 11:1 your wasting your $'s.  I ran pump 92 (no ethanol) in a 10.25:1 race engine with no issues.

I use the same in my 550 on the street to avoid any ethanol storage issues (stabilizer also added).

[seanbarney41]

No problem Justin, I ran race fuel in mine with no problems, as long as you flush it out before storage.
Oxygenated fuel can turn valves and seats rusty if not flushed out.

Sam.

Good to know, Sam.  I thought ethanol-free race gas was okay to keep in the tank, especially compared to ethanol-based fuels getting gummy with non-use.

careful, not all high octane/race fuel is "oxygenated".  It is only the "oxygenated" varieties that cannot be stored effectively.

[bwaller]

Be careful to flush any race gas in my opinion. Storage is another thing.

To the original poster, TG's point is correct about compression ratios & octane. If you experience any detonation with off the shelf 836 pistons, check ignition issues first. Race gas on the street would be an incredible nuisance.

[HondaMan]

No problem Justin, I ran race fuel in mine with no problems, as long as you flush it out before storage.
Oxygenated fuel can turn valves and seats rusty if not flushed out.

Sam.

Good to know, Sam.  I thought ethanol-free race gas was okay to keep in the tank, especially compared to ethanol-based fuels getting gummy with non-use.

The really nasty part of the ethanol gas is: it absorbs moisture from the air, then mixes it with the gas as a heavier-than-gas molecule. After a winter of this, you will find a layer (about 10% deep, if your mix is 10% ethanol like ours) of brownish-colored gas in the bottom of the tank. This is the (ethanol + water) stuff, and it causes rust, even where the tank is wet (like, a form of underwater rust) because it is oxygenated, as well.

I have found that mixing in either Marvel Mystery Oil or even regular 10w Valvoline with the last tank of the season inhibits the water. I am currently experimenting with this again now, as the riding season here is pretty much over.

The octane question: higher octane burns slower than lower octane. Ethanol burns slower than both. The higher-compression engines need the higher octane to resist self-ignition in that hotter head: ethanol does this all by itself, being just plain difficult to ignite. Usually, if you burn higher octane than you need, it will tend to foul the sparkplugs if it does not make any performance difference (i.e., the engine does not need it, so some of it does not burn).

For example: my 750 will run fine in city traffic on 87 (midgrade) fuels, but is not happy at the 80-90+ freeway speeds we have here. The premium gas wakes up around 5000 RPM on my bike, so as I approach the 80 MPH mark with premium the bike just takes off into it (as this is where the cam starts it work). If I have the midgrade aboard, I have to roll on more throttle to pick it up. But...if I run premium all the time in mostly city surface street traffic, it will starts fouling the plugs after about 1500-2000 miles.

[SOHC4 Cafe Racer Fan]

I don't store any tank too long, but I add Seafoam to any new tank of gas (ethanol pump gas).  I'd rather run something better that will neither gum up or facilitate rust.

[Justin]

I don't store any tank too long, but I add Seafoam to any new tank of gas (ethanol pump gas).  I'd rather run something better that will neither gum up or facilitate rust.

Don, I really love SeaFoam!!

I'm running the 10.5:1 CR 836cc JE pistons
Not such high performance as many here, but I was excited at the prospects of ditching ethanol fuels.
Puregas.com has a map of the ethanol free petrol stations in the US. Back home in Perth the pumps are 91, 95, & 98 RON octane.. Which I don't think is too different from California's 87, 89, 91 scheme MON.

I'm just curious if there is a reasonable cost-benefit factor to buying the ethanol free 96 or 98 octane available locally.



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[Justin]

not much use in higher octanes if you are not increasing compression ratio. higher octane doesnt mean higher enrgy, just more detonation resistance that lets you run higher CR, and thats where the extra power comes from.
complex subject, i'd say 11:1 is ok with 98 but what if you need to refuel in some other place that doesnt have it?

Bingo...

Mick, 
Www.puregas.com shows stations in the US that have ethanol free petrol, many of them have higher octane race fuels, but mostly the CB doesn't do much touring. I have other less performance oriented bikes that do the touring.


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[Justin]

As TG said, unless your running over 11:1 your wasting your $'s.  I ran pump 92 (no ethanol) in a 10.25:1 race engine with no issues.

I use the same in my 550 on the street to avoid any ethanol storage issues (stabilizer also added).

TT, where do you live that you're getting 92 ethanol free?
What stabiliser are you using? I generally ride all year because weather is nice in this part of California, so I don't use stabiliser most of the time. But it seems that I am spending more and more time abroad for work and my brother doesn't always make sure the bikes are ran/ridden regularly. Maybe I should think about storage and stabiliser


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[Justin]

No problem Justin, I ran race fuel in mine with no problems, as long as you flush it out before storage.
Oxygenated fuel can turn valves and seats rusty if not flushed out.

Sam.

Good to know, Sam.  I thought ethanol-free race gas was okay to keep in the tank, especially compared to ethanol-based fuels getting gummy with non-use.

The really nasty part of the ethanol gas is: it absorbs moisture from the air, then mixes it with the gas as a heavier-than-gas molecule. After a winter of this, you will find a layer (about 10% deep, if your mix is 10% ethanol like ours) of brownish-colored gas in the bottom of the tank. This is the (ethanol + water) stuff, and it causes rust, even where the tank is wet (like, a form of underwater rust) because it is oxygenated, as well.

I have found that mixing in either Marvel Mystery Oil or even regular 10w Valvoline with the last tank of the season inhibits the water. I am currently experimenting with this again now, as the riding season here is pretty much over.

The octane question: higher octane burns slower than lower octane. Ethanol burns slower than both. The higher-compression engines need the higher octane to resist self-ignition in that hotter head: ethanol does this all by itself, being just plain difficult to ignite. Usually, if you burn higher octane than you need, it will tend to foul the sparkplugs if it does not make any performance difference (i.e., the engine does not need it, so some of it does not burn).

For example: my 750 will run fine in city traffic on 87 (midgrade) fuels, but is not happy at the 80-90+ freeway speeds we have here. The premium gas wakes up around 5000 RPM on my bike, so as I approach the 80 MPH mark with premium the bike just takes off into it (as this is where the cam starts it work). If I have the midgrade aboard, I have to roll on more throttle to pick it up. But...if I run premium all the time in mostly city surface street traffic, it will starts fouling the plugs after about 1500-2000 miles.

Engine oil? In the tank? How much is adequate? Do you store your bikes with the fuel tank full?
Good to know about touring vs goofing around town


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[HondaMan]

No problem Justin, I ran race fuel in mine with no problems, as long as you flush it out before storage.
Oxygenated fuel can turn valves and seats rusty if not flushed out.

Sam.

Good to know, Sam.  I thought ethanol-free race gas was okay to keep in the tank, especially compared to ethanol-based fuels getting gummy with non-use.

The really nasty part of the ethanol gas is: it absorbs moisture from the air, then mixes it with the gas as a heavier-than-gas molecule. After a winter of this, you will find a layer (about 10% deep, if your mix is 10% ethanol like ours) of brownish-colored gas in the bottom of the tank. This is the (ethanol + water) stuff, and it causes rust, even where the tank is wet (like, a form of underwater rust) because it is oxygenated, as well.

I have found that mixing in either Marvel Mystery Oil or even regular 10w Valvoline with the last tank of the season inhibits the water. I am currently experimenting with this again now, as the riding season here is pretty much over.

The octane question: higher octane burns slower than lower octane. Ethanol burns slower than both. The higher-compression engines need the higher octane to resist self-ignition in that hotter head: ethanol does this all by itself, being just plain difficult to ignite. Usually, if you burn higher octane than you need, it will tend to foul the sparkplugs if it does not make any performance difference (i.e., the engine does not need it, so some of it does not burn).

For example: my 750 will run fine in city traffic on 87 (midgrade) fuels, but is not happy at the 80-90+ freeway speeds we have here. The premium gas wakes up around 5000 RPM on my bike, so as I approach the 80 MPH mark with premium the bike just takes off into it (as this is where the cam starts it work). If I have the midgrade aboard, I have to roll on more throttle to pick it up. But...if I run premium all the time in mostly city surface street traffic, it will starts fouling the plugs after about 1500-2000 miles.

Engine oil? In the tank? How much is adequate? Do you store your bikes with the fuel tank full?
Good to know about touring vs goofing around town


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I don't usually INTEND to store my bike(s) with the tanks full, but here in Colorado the weather after September is extremely unpredictable.  You can be riding to work in shirt sleeves Monday, shoveling a foot of snow on Tuesday, driving the car until Thursday, then back on the bike Friday. When this season comes, I like to try to have some gas in it, just in case a ride could be had, but sometimes it just ends up staying too cold, or snowy, or wet, or...? - and then it's Spring.

The oil hasn't seemed to matter as to which kind I've used, with one exception: some of the 2-stroke synthetic oils (almost no detergent?) can gum up the carb slides and make them sticky enough that I've had to pull them off for cleaning, come Spring.

[Kickstart]

As others have said... be careful that you're actually getting ethanol free gas.  Sometimes these gas stations sell "race gas" and advertise being ethanol free, but not all the grades they sell are really non-oxygenated (ethanol free).

Ask for the trade name and grade name, and look it up online to verify.  Usually these places sell either VP or Sunoco gas.
http://www.vpracingfuels.com/master-fuels-table
http://www.racegas.com/fuel/compare

If it is non-oxygenated (aka ethanol free) the shelf life is usually rated in years and should be a good option to store in the tank over winter.  Both VP and Sunoco sell an ethanol free and lead free race gas - handy if you have a newer bike that can't handle the lead.  Or don't want to have to worry about accidentally pouring it in your car and ruining the catalytic converter.

Also, as others have said, you really don't need higher octane beyond 89 R+M/2 octane, but I suspect anything under 100 will be fine. 

Going too high can possibly cause problems.  If the octane is too high for what you're engine is designed for you wont get as much fuel vaporization, end up with more unburnt gas, and subsequently more gas being absorbed into the engine oil (breaking down your oil faster than normal requiring more frequent oil changes).

 

[Justin]

As others have said... be careful that you're actually getting ethanol free gas.  Sometimes these gas stations sell "race gas" and advertise being ethanol free, but not all the grades they sell are really non-oxygenated (ethanol free).

Ask for the trade name and grade name, and look it up online to verify.  Usually these places sell either VP or Sunoco gas.
http://www.vpracingfuels.com/master-fuels-table
http://www.racegas.com/fuel/compare

If it is non-oxygenated (aka ethanol free) the shelf life is usually rated in years and should be a good option to store in the tank over winter.  Both VP and Sunoco sell an ethanol free and lead free race gas - handy if you have a newer bike that can't handle the lead.  Or don't want to have to worry about accidentally pouring it in your car and ruining the catalytic converter.

Also, as others have said, you really don't need higher octane beyond 89 R+M/2 octane, but I suspect anything under 100 will be fine. 

Going too high can possibly cause problems.  If the octane is too high for what you're engine is designed for you wont get as much fuel vaporization, end up with more unburnt gas, and subsequently more gas being absorbed into the engine oil (breaking down your oil faster than normal requiring more frequent oil changes).

 

Good advice kickstart.
PS, I don't live in an "enhanced" smog requirement county. My cars don't need cats

I'm pretty sure all you can get around here for the race petrols are Sunoco but I will check the station's fuel trucks to verify. They also sell the standard 87/89/91 unleaded varieties and diesel. If I could get the 87/89/91 stuff in ethanol free it would greatly ease my concerns, but it seems those are hard to find in California's Bay Area and Sierra foothills

I'm certain that I don't need "race" fuel in any of my vehicles, and I would prefer to use 87 & 91 as required, but they're all polluted with ethanol (up to 15%)


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[Kickstart]

As others have said... be careful that you're actually getting ethanol free gas.  Sometimes these gas stations sell "race gas" and advertise being ethanol free, but not all the grades they sell are really non-oxygenated (ethanol free).

Ask for the trade name and grade name, and look it up online to verify.  Usually these places sell either VP or Sunoco gas.
http://www.vpracingfuels.com/master-fuels-table
http://www.racegas.com/fuel/compare

If it is non-oxygenated (aka ethanol free) the shelf life is usually rated in years and should be a good option to store in the tank over winter.  Both VP and Sunoco sell an ethanol free and lead free race gas - handy if you have a newer bike that can't handle the lead.  Or don't want to have to worry about accidentally pouring it in your car and ruining the catalytic converter.

Also, as others have said, you really don't need higher octane beyond 89 R+M/2 octane, but I suspect anything under 100 will be fine. 

Going too high can possibly cause problems.  If the octane is too high for what you're engine is designed for you wont get as much fuel vaporization, end up with more unburnt gas, and subsequently more gas being absorbed into the engine oil (breaking down your oil faster than normal requiring more frequent oil changes).

 

Good advice kickstart.
PS, I don't live in an "enhanced" smog requirement county. My cars don't need cats

I'm pretty sure all you can get around here for the race petrols are Sunoco but I will check the station's fuel trucks to verify. They also sell the standard 87/89/91 unleaded varieties and diesel. If I could get the 87/89/91 stuff in ethanol free it would greatly ease my concerns, but it seems those are hard to find in California's Bay Area and Sierra foothills

I'm certain that I don't need "race" fuel in any of my vehicles, and I would prefer to use 87 & 91 as required, but they're all polluted with ethanol (up to 15%)


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I think they advertise as "race" because they're not street legal... In fact, I don't believe there are any non-oxygenated fuels that are street legal, at least not in most states.  You'll most likely be purchasing a 5 gallon drum of "race" gas.  I highly doubt anyone sells it out of a pump (unless it's a pump at a race track), and if they do sell from a pump at a regular gas station claiming it's ethanol free, I'd be very suspicious.

VP racing sells a gas that I hear is popular with landscapers: C9 - it's non-oxygenated and non-leaded, so they don't have to worry about it gumming up when stored and you can use it anywhere.  It's R+M/2 octane level is only 96 (so not too high).  I used it myself at the track and was very happy with it.  Just be careful that you don't get the c9-premix (they sell a version that has two stroke oil premixed in).

For Sunoco, it looks their Optima grade would be what you're looking for.  Non-oxygenated and non-leaded - 95 octane:
http://www.racegas.com/fuel/21

[Justin]

As others have said... be careful that you're actually getting ethanol free gas.  Sometimes these gas stations sell "race gas" and advertise being ethanol free, but not all the grades they sell are really non-oxygenated (ethanol free).

Ask for the trade name and grade name, and look it up online to verify.  Usually these places sell either VP or Sunoco gas.
http://www.vpracingfuels.com/master-fuels-table
http://www.racegas.com/fuel/compare

If it is non-oxygenated (aka ethanol free) the shelf life is usually rated in years and should be a good option to store in the tank over winter.  Both VP and Sunoco sell an ethanol free and lead free race gas - handy if you have a newer bike that can't handle the lead.  Or don't want to have to worry about accidentally pouring it in your car and ruining the catalytic converter.

Also, as others have said, you really don't need higher octane beyond 89 R+M/2 octane, but I suspect anything under 100 will be fine. 

Going too high can possibly cause problems.  If the octane is too high for what you're engine is designed for you wont get as much fuel vaporization, end up with more unburnt gas, and subsequently more gas being absorbed into the engine oil (breaking down your oil faster than normal requiring more frequent oil changes).

 

Good advice kickstart.
PS, I don't live in an "enhanced" smog requirement county. My cars don't need cats

I'm pretty sure all you can get around here for the race petrols are Sunoco but I will check the station's fuel trucks to verify. They also sell the standard 87/89/91 unleaded varieties and diesel. If I could get the 87/89/91 stuff in ethanol free it would greatly ease my concerns, but it seems those are hard to find in California's Bay Area and Sierra foothills

I'm certain that I don't need "race" fuel in any of my vehicles, and I would prefer to use 87 & 91 as required, but they're all polluted with ethanol (up to 15%)


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I think they advertise as "race" because they're not street legal... In fact, I don't believe there are any non-oxygenated fuels that are street legal, at least not in most states.  You'll most likely be purchasing a 5 gallon drum of "race" gas.  I highly doubt anyone sells it out of a pump (unless it's a pump at a race track), and if they do sell from a pump at a regular gas station claiming it's ethanol free, I'd be very suspicious.

VP racing sells a gas that I hear is popular with landscapers: C9 - it's non-oxygenated and non-leaded, so they don't have to worry about it gumming up when stored and you can use it anywhere.  It's R+M/2 octane level is only 96 (so not too high).  I used it myself at the track and was very happy with it.  Just be careful that you don't get the c9-premix (they sell a version that has two stroke oil premixed in).

For Sunoco, it looks their Optima grade would be what you're looking for.  Non-oxygenated and non-leaded - 95 octane:
http://www.racegas.com/fuel/21

Cheers, mate. The station near my brother's house sells it from the pump: 96, 98, & 101 (they claim it's ethanol free, but I haven't verified), but I can buy drums from the Matco Tools guy, I think. I've seen their race fuel pumps, they padlock them, but it is a pump just like the regular ones.


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[Kickstart]

Wow... I'm in PA which has laws requiring the sale of oxygenated gas... I figured CA would surely be even more restrictive, but I guess not in this case.

That's good news for you, since I assume it's a little cheaper if they're selling enough volume to be using a pump.

[SOHC4 Cafe Racer Fan]

As others have said... be careful that you're actually getting ethanol free gas.  Sometimes these gas stations sell "race gas" and advertise being ethanol free, but not all the grades they sell are really non-oxygenated (ethanol free).

Ask for the trade name and grade name, and look it up online to verify.  Usually these places sell either VP or Sunoco gas.
http://www.vpracingfuels.com/master-fuels-table
http://www.racegas.com/fuel/compare

If it is non-oxygenated (aka ethanol free) the shelf life is usually rated in years and should be a good option to store in the tank over winter.  Both VP and Sunoco sell an ethanol free and lead free race gas - handy if you have a newer bike that can't handle the lead.  Or don't want to have to worry about accidentally pouring it in your car and ruining the catalytic converter.

Also, as others have said, you really don't need higher octane beyond 89 R+M/2 octane, but I suspect anything under 100 will be fine. 

Going too high can possibly cause problems.  If the octane is too high for what you're engine is designed for you wont get as much fuel vaporization, end up with more unburnt gas, and subsequently more gas being absorbed into the engine oil (breaking down your oil faster than normal requiring more frequent oil changes).

 

Good advice kickstart.
PS, I don't live in an "enhanced" smog requirement county. My cars don't need cats

I'm pretty sure all you can get around here for the race petrols are Sunoco but I will check the station's fuel trucks to verify. They also sell the standard 87/89/91 unleaded varieties and diesel. If I could get the 87/89/91 stuff in ethanol free it would greatly ease my concerns, but it seems those are hard to find in California's Bay Area and Sierra foothills

I'm certain that I don't need "race" fuel in any of my vehicles, and I would prefer to use 87 & 91 as required, but they're all polluted with ethanol (up to 15%)


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I think they advertise as "race" because they're not street legal... In fact, I don't believe there are any non-oxygenated fuels that are street legal, at least not in most states.  You'll most likely be purchasing a 5 gallon drum of "race" gas.  I highly doubt anyone sells it out of a pump (unless it's a pump at a race track), and if they do sell from a pump at a regular gas station claiming it's ethanol free, I'd be very suspicious.

VP racing sells a gas that I hear is popular with landscapers: C9 - it's non-oxygenated and non-leaded, so they don't have to worry about it gumming up when stored and you can use it anywhere.  It's R+M/2 octane level is only 96 (so not too high).  I used it myself at the track and was very happy with it.  Just be careful that you don't get the c9-premix (they sell a version that has two stroke oil premixed in).

For Sunoco, it looks their Optima grade would be what you're looking for.  Non-oxygenated and non-leaded - 95 octane:
http://www.racegas.com/fuel/21

Thanks for the advice, Chris!  On the VP website, I did not see C9, but I did see C10.  Is that what you were talking about (unleaded/non-oxygenated 96 octane)?

[Kickstart]

...

Thanks for the advice, Chris!  On the VP website, I did not see C9, but I did see C10.  Is that what you were talking about (unleaded/non-oxygenated 96 octane)?

The VP fuels website isn't very user friendly. 

They mention both C9 and C10 on this page (about half way down): http://www.vpracingfuels.com/vp-racing-fuels.html - but the buttons/links to the spec sheets don't actually link the to the spec sheet!

C9 is also listed in their master fuel table: http://www.vpracingfuels.com/master-fuels-table (with a working link to the spec sheet) - but confusingly, the spec sheet states 94 R+M/2 octane - so I guess the 96 octane is a typo (or the 94 in the spec sheet is a typo)?

C10 appears to have a slightly higher octane rating, but otherwise seems very similar.

I ended up buying C9 because that's what they had at my local bike shop (which also sells generators and pressure washers) - they mentioned to me that it's popular with landscapers... but at $11-$12 a gallon I assume they would just use it towards the end of the season.  I only started using it when my bike became a dedicated race bike, as I only do 3-4 race weekends a year and I didn't want to mess with draining the gas between events. I also like to believe it has a higher BTU (and thus more hp) but I honestly couldn't tell a difference.  I've also thought about using for winter storage on my street bikes - but again you're talking approximately $50 to fill up a tank.

I've used the VP Vintage grade (higher octane and leaded - which also seemed to work well) - because my local shop ran out of C9 but had a couple cans of the vintage grade   ..... but I'd recommend the non-leaded as it's less of a headache if you want to drain your tank back into a gas can and not have to keep track of which can has leaded vs non-leaded gas in it.

[Justin]

Wow... I'm in PA which has laws requiring the sale of oxygenated gas... I figured CA would surely be even more restrictive, but I guess not in this case.

That's good news for you, since I assume it's a little cheaper if they're selling enough volume to be using a pump.

99% of petrol stations  in California sell ethanol mixed fuels. 15% ethanol, 85% petrol I believe. But I can find stations that sell ethanol free fuels, many are in So Cal and in Northern California's 101 highway region. Not too many near where I live.

With regard to the pumps, it's pretty good. I feel bad you're paying such a premium for it. It's $5-$9 per gallon usually, depending on what octane you're getting. But this station has several underground tanks dedicated just to the "race" fuels, I imagine that keeps costs down. And they also sell lots of the everyday fuels for cheap $2.33/gallon currently for 87.
The station is right off the highway along a major commuters' route so they seem to be really busy.


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