Jump to content
Sign in to follow this  

what race fuel are you running

Recommended Posts

I have had great results with VP U-4 mixed with 94 octane pump gas. Now I am trying C-12 mixed 50/50 with 94 octane. I have a high comp. piston and some head mods but nothing extreme. Bike definitely runs better on the race gas because its jetted for it. What are you running?

Share this post


Link to post
Share on other sites

93 Pump then to VP U-4, Then back to Pump 93. Could deff feel and liked the difference but when the 5 Gal can went from $50 to $90 in my area in 1 month I went back to Pump 93 and just jetted my bike correctly and cant even tell I went back to the Pump 93. My jetting specs for my 06 Kx250F at Sea level is, 170 Main, Stock Pilot, JD Red Needle with Clip at 4th position. Changed Leak jet from the stock 55 to a 50 and my Air screw is at 2 1/2 turns out. I also have a Boysen Quickshot and a Powernow.

Share this post


Link to post
Share on other sites

the highest octane i can find in nebraska is 91 so i got 30 gal. of 91 and put it in a drum and added 3 gal. of 127 octane avgas. it brings the octane up to about 95 and it runs good in my stock '06 engine plus the avgas has a little lead in it to help with lubrication.

Share this post


Link to post
Share on other sites

I run straight C-12 and im running a je high comp piston too. just only thing because of the porting and hot cams i had to rejet to a 45 pilot jet and leanest clip position on the needle and it barks real nice when i want power. I dont think ill run 50/50 anymore since C-12 is only $6 a gallon where im getting it and since i have done some mods

Share this post


Link to post
Share on other sites

Renegade 110 @ 50-50 with 93 pump gas. Running in a 262 big bore with no problems (but jetting changed).

Share this post


Link to post
Share on other sites

U2 in the smokers and U4 the 450's is it pricey? YUP BUT OOOOOOOOO THAT SMELL! AND WENT UP ( WAY UP) ON THE JETTING,so for me it's worth it!!!

Share this post


Link to post
Share on other sites

some friends of mine are running the vp u4 stuff, they seem to really like it, it puts off quite an odor, but at $12.50 a gallon there is no way i will be running it through my bike, maybe if i go to a national or somthing, but that is way to expensive to be just playing around on!

Share this post


Link to post
Share on other sites

I stopped using U4 when it got over $8 a gallon. Since the oxygenation seems to be the ingredient that gives it its potency, does anyone know of any additive or reasonable option to increase the oxygenation of pump gas?

Share this post


Link to post
Share on other sites
I stopped using U4 when it got over $8 a gallon. Since the oxygenation seems to be the ingredient that gives it its potency, does anyone know of any additive or reasonable option to increase the oxygenation of pump gas?

Thats a good question. Anyone have an Idea??

Share this post


Link to post
Share on other sites

In my KX i run 98 octane pump fuel, and octane booster which ups it to 105 octane.

The 250F gets straight 98 octane pump fuel. runs fine on it, no need to change.

Share this post


Link to post
Share on other sites

I use 4 gallons of 91 pump gas to 1 gallon of 108 octane C-12. Makes it about a 94 Octane cocktail. Bike runs nice but backfires some when you get off the throttle so it must be a little lean in the jetting. Got to look into that before the next season starting in October.!

Share this post


Link to post
Share on other sites
I stopped using U4 when it got over $8 a gallon. Since the oxygenation seems to be the ingredient that gives it its potency, does anyone know of any additive or reasonable option to increase the oxygenation of pump gas?

Benzine AKA O2 :thumbsup:

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×