race fuel?????

[Wills77]

well i have a ltr with a full race motor(port,polish,cams,valves,piston... etc)
its a 12.8:1 je piston

now im wondering about fuel.. i have been running klotz113 all season but have had alot of problems with it clogging my injector and my builder says that it builds up a schalack.

klotz 113 - what i ran this year. 20 min drive for me

sunoco 110 - my builder recomends but is a 2 hour trip and i was told by another person that it is a "dirty fuel"

vp c12 - is leaded so i was told it will do the same as klotz. 30 min drive

vp u4.2 - ????? all i know is its only 30 min away

vp motorsports 109 - ????? same as above


any kind of input or experience is appreciated

[09RappySe]

You should be running pump gas (93) anything more is a waste of money and power...I am running 13.5:1 at sea level, and initially ran premium, with no problems, but am on the edge on hot days so I mix a little 110 and 93.

[fearlessfred]

Originally posted by 09RappySe
You should be running pump gas (93) anything more is a waste of money and power...I am running 13.5:1 at sea level, and initially ran premium, with no problems, but am on the edge on hot days so I mix a little 110 and 93.
x2 i agree with rappy,i cant see u needing over 100 octane.stock compressiom is 11.71 to much octane is a waste of money and horse power

[Wills77]

sorry i forgot to mention that i do mix it 50/50 with 93

i know its still pretty low compression for a race motor and i brought that up to my builder that i could run pump gas and he gets real defensive saying that this motor needs race fuel... idk why?

is it ok to mix the motorsport 109 with pump fuel since its unleaded and oxygenated

[fearlessfred]

Originally posted by Wills77
sorry i forgot to mention that i do mix it 50/50 with 93

i know its still pretty low compression for a race motor and i brought that up to my builder that i could run pump gas and he gets real defensive saying that this motor needs race fuel... idk why?

is it ok to mix the motorsport 109 with pump fuel since its unleaded and oxygenated your motor builder is not out of line having u run 50/50. a little extra insurance is good, because at the pump u dont know that your getting 93 octane ( when i was a kid and worked at a station the owner would have me pump regular into the prem. tank and it wasnt to make more money , but because he didnt wont people driving away because he didnt have prem.) so always buy from a busy station. i dont know what fuels can be mixed.somebody on here will know

[Hanes15]

I have a high comp piston intake and exhaust cams and I run sunoco standard. I dont know if its a dirty fuel, my filter gets just as dirty when I was running pump fuel. I only use the sunoco compared to vp becasue its almost 15$ cheaper for 5 gallons.

It is important to run a mixed ratio or straight race gas when using a high compression piston. It is also important that your bike is tuned for the fuel you use. You dont want to run say vp110c and have your bike tuned to it and then decide to run vpu4.2 one weekend because it is oygenated and your bike will run lean.

I say choose one fuel. From your choices vpu4.2 sounds the best because it is close and you dont have to drain your fuel system after every use and during storage as it will not clogg up your fuel system. The vpc12 can clogg the system. If you could I would just run the vp110c if they have it or can get just becasue its cheaper.

[Wills77]

thanks for the info.
does the vp motorsport 109 require you to drain it after every use or not?
i used to run c12 in my yfz but never tried it in my ltr.
i never tried u4.2

[Hanes15]

I am unsure if motosport 109 needs to be drained. It is oxygenated so I would suggest it. It is unleaded which is good cause it is less harsh on the fuel system. Leaded fuel is hard on the fuel hoses.

I messed up last night and said that c12 would clogg the system and that was wrong it will not.

U4.2 was designed to be user friendly. Its slightly oxygenated so it adds power but they made it in a way it does not need to be drained so its easy to use.

[Wills77]

Originally posted by Hanes15
I am unsure if motosport 109 needs to be drained. It is oxygenated so I would suggest it. It is unleaded which is good cause it is less harsh on the fuel system. Leaded fuel is hard on the fuel hoses.

I messed up last night and said that c12 would clogg the system and that was wrong it will not.

U4.2 was designed to be user friendly. Its slightly oxygenated so it adds power but they made it in a way it does not need to be drained so its easy to use.

thanks for all the info. i appreciate it. im going to go with the u4.2 mixed with some 93. i ride a couple times a week so it would be a pain having to drain the motosport after every time i ride.

[eastside 400]

im not sure if i would really mix the u4.2, i dont think the oxy fuel should be mixed really. also the u4.2 is a PITA usually, gums up everything super quick. i dont think they make it anymore the newest version is u4.4

[Wills77]

Originally posted by eastside 400
im not sure if i would really mix the u4.2, i dont think the oxy fuel should be mixed really. also the u4.2 is a PITA usually, gums up everything super quick. i dont think they make it anymore the newest version is u4.4

ohh thanks chris... i thaught i heard that before but wasnt sure.
hows your shoulder? i heard you messed it up pretty bad

sooo should i go with the c12?

[eastside 400]

yea its up to you, if your gonna cut the u4 then you wouldnt really see any gain in performance and that stuff is alot more then c12. i would just cut the c12 50/50. My shoulder is getting better, had to get surgery the beginning of august, just got done therapy last week and its starting to get back to normal. prolly get back on the bike late november or something

[Wills77]

yea ill go with the c12
i hope it heals up good for you... whered it happen at? i dont think ive seen you since raceway park... we had a pretty good race goin that day.... what are your plans for next season

[eastside 400]

crashed at atco, doing a dbl dbl dbl rythem section as dbl triple single and i hit i slick spot off the lip or something and came up short and broke my axle. yea raceway was fun...prolly just race some d6 next year, i got a crf250 now so i wanna ride that more

[Dirtjunkie85]

i have a 13.5 : 1 piston and i just get 100 octane from a pump around town and it works way good!

[panici33]

I run U4.4. Before that I ran U4.2, and I have had no problems with either.