91 octane or VP race gas?

Getting back into riding...Bought a 2011 yz250F in December 12' its still stock, Will high test fuel make a difference in power, performance or longevity of motor ? I ride mostly SoCal desert, "Johnson Valley"

do you even know what "high test" means?

 

and which VP race gas?  they make about 29 different flavors you could put in your bike.

of those 29 about 11 are directly made for bikes.

 

what you get when you buy VP race fuel (of any flavor) or anybody elses "race fuel" is typically a controlled quality product with out all the tash dumped in from the refinery.

 

lack of alky will be better for the carb.

I would also add that on a stock bike the only fuel that will really give you any power advantage would be oxygenated fuel. VP has U4.4 and I have used the .2 version in the past and liked it. Any none oxyegenated high octane race fuel would be a waste of your money IMHO.

Thanx, just wondering if it is was worth the dough before it was necessary.

do you even know what "high test" means?

and which VP race gas? they make about 29 different flavors you could put in your bike.

of those 29 about 11 are directly made for bikes.

what you get when you buy VP race fuel (of any flavor) or anybody elses "race fuel" is typically a controlled quality product with out all the tash dumped in from the refinery.

lack of alky will be better for the carb.

High Test = High Octane

(Not Regular)

-So now you know-

I didnt even think of the alcohol in pump gas factor. That ruins the seals,right?

High Test = High Octane

(Not Regular)

-So now you know-

 

define high octane....if you say its not regular.  and 87 is regular...then 89 midgrade is high octane.

 

lol you dont even know what alky does?

define high octane....if you say its not regular.  and 87 is regular...then 89 midgrade is high octane.

 

lol you dont even know what alky does?

What does Alky do?

it is highly corrosive.

and

it sucks water

Pump 91 is fine. Even the crap they sell here in socal. Just buy from a busy station so it is fresh. Never seen a stock bike around here with issues with 91 pump gas. If your not gonna ride for a month or longer drain the carb.

if you have a small muni airport try AvGas . It's ethanol free , is 100 octane and can sit up to a year with no probs. It's 6 bux a gallon.

It doesnt hurt valves , the maint sched and lifespan of valves comes around long before avgas would have time to do anything .

Read around, there's a whole internet of people that have been running it in everything from bikes to sleds to whatever ...for 10 , 20 , 30 yrs .

You will also have people post "it's only meant for high altitude constant rpm" or "it will ruin your valves" or it's messy... It's fine for bikes.

Anyone who run's it and maint's their bike correctly can tell you this. And yes, it does make a little more power but mainly I run it

because I cant afford to run C12 , U4.4 or T9 year round but I can afford Avgas since it's just a little more than pump 93 and I avoid all

the ethanol associated probs . If I could buy ethanol free pump, i'd probably buy that and save the trip but it's not avail here.

I do like VP C12 if a race in the cooler months and U4.4 or T9 in the hottest months...seasons swing from 80's-90's summer

and 0-30 winter around here .  I run "warm months jetting" and "cool months" jetting , the u4.4 saves me a 3rd jetting change in the hottest month and without it

I just run a little rich.

if you have a small muni airport try AvGas . It's ethanol free , is 100 octane and can sit up to a year with no probs. It's 6 bux a gallon.

It doesnt hurt valves , the maint sched and lifespan of valves comes around long before avgas would have time to do anything .

Read around, there's a whole internet of people that have been running it in everything from bikes to sleds to whatever ...for 10 , 20 , 30 yrs .

You will also have people post "it's only meant for high altitude constant rpm" or "it will ruin your valves" or it's messy... It's fine for bikes.

Anyone who run's it and maint's their bike correctly can tell you this. And yes, it does make a little more power but mainly I run it

because I cant afford to run C12 , U4.4 or T9 year round but I can afford Avgas since it's just a little more than pump 93 and I avoid all

the ethanol associated probs . If I could buy ethanol free pump, i'd probably buy that and save the trip but it's not avail here.

I do like VP C12 if a race in the cooler months and U4.4 or T9 in the hottest months...seasons swing from 80's-90's summer

and 0-30 winter around here . I run "warm months jetting" and "cool months" jetting , the u4.4 saves me a 3rd jetting change in the hottest month and without it

I just run a little rich.

I thought of AvGas too, I used to work at Riverside airport. I think I will swing by and fill a jug.

define high octane....if you say its not regular.  and 87 is regular...then 89 midgrade is high octane.

 

lol you dont even know what alky does?

 

Why do you so often have to be so condescending in your replies?  Grow up!

 

_________________________________________________________________

 

 

 

SoCal250f, high octance fuel doesn't necessarily mean more power although many people - myself included - notice a difference when running it.  "Race gas" accomodates higher compression engines that provide more power (without the detonation that lower octane gas can result in); race gas also tends to run cooler (cooler and slower burn).  I run 110 octane cut with premium pump 3:2 because we tried out a Gytr high-comp in my son's 250f and a minimum of 100 octane is recommended.  BUT . . . I run it in my 250xc and there's no doubt that I can feel the difference.

 

The AV gas is worth trying as a start. 

 

Here's an old race engine builder's concoction for race fuel: 4gal AV 100 octane, 1 gal toluene, 28 oz K1 kerosene.  Don't know if this would be cost effective these days, but the toluene drives the octane up, the kerosene keeps the solvency of the toluene in check.  Haven't ran this for some time, might give it a try soon.

Edited by Yamajeb

Toluene definetely works. I used to put 32 oz into 3 gals gas and it made a difference. Beyond that it got mushy , guess the mix got too dense/rich for my jetting ....a little does work though

You only need a high enough octane to stop detonation.  Anything beyond that does nothing.  For my motor, a mix of 60% 91 pump gas, and 40% 110 race gas does the trick.  This is approx 99 Octane....  A higher compression piston, and more aggressive timing may require higher octane.

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