Free U4..Can I run it?

[Nick110]

I can get free U4 but Im not sure if I can run it. I have a 06 450r with 04 crf cam and 13.5.1 wiseco piston. Is it safe to run straight U4 or do I have to mix it. Will I have to rejet for it? Thanks guys.

[300exguy125]

im not sure if its safe for your quad unless you did extensive motor mods but i think you got to mix that stuff becuase i would think that that pure U4 in your engine would cause something to explode not sure though

[Nick110]

Oh well I just put it and got it running and damn does she run well. Its only 106 octane and oxygenated so Im pretty sure I can run it straight.

[pro-rider46]

yeah you run like 115+ octane with that high of piston

btw its u4 he is putting, not c4 so nothing going to explode:D

[400exrider707]

So far nothing anyone has posted makes any sense... U4 will not make anything explode... sure you can run it but a re-jet is necessary as its oxygenated.

[Nick110]

Originally posted by 400exrider707
So far nothing anyone has posted makes any sense... U4 will not make anything explode... sure you can run it but a re-jet is necessary as its oxygenated.

What would u recommend me jetting to? And would it be OK to run the jetting I have now for the weekend.

[FHKracingZ]

deffinatly run it if u can. If ure quad is jetted right, you will see any were from 1.5-2.5 horse gain just from U4 or MR9 fuel. no lie.

[Nick110]

Originally posted by FHKracingZ
deffinatly run it if u can. If ure quad is jetted right, you will see any were from 1.5-2.5 horse gain just from U4 or MR9 fuel. no lie.

How would i jet it for the U4. When I got it running it sounded like it was running great, no popping, idleing smooth, no hesitation on throttle.

[FHKracingZ]

Getting should be normal gasoline jetting. If u have a chance get it on a dyno for a a/f mixture ratio. You wanna be around 13 give or take. Besides the performance, its gotta be the smell that is so damn cool!

[Nick110]

Originally posted by FHKracingZ
Getting should be normal gasoline jetting. If u have a chance get it on a dyno for a a/f mixture ratio. You wanna be around 13 give or take. Besides the performance, its gotta be the smell that is so damn cool!

Ok i dont know if ill be able to get it on a dyno but ill try.

And the smell.... well its like candy haha

[eganracing]

when I used to run U4 it left alot of residue everywhere in my fuel system. someone once told me that you either need to ride it at least every 2 days or drain the system after riding. I have no idea if this is true but maybe someone can chime in on this.

on another note that fuel made my quad noticably faster but I couldnt stand the smell of it in my garage so I changed to a different type.

[400exrider707]

You should drain your carb after every use, and you cant leave it in the barrel once you open it up for very long it needs to be used. The fuel will eat the seals in the carb.

Also jetting shouldn't be what you used for regular pump gas either, it should be different. The U4 is oxygenated, any time you are getting more air in you need more fuel to match. You need to jet richer. I cant give exact numbers, but if you say its running good, then perhaps your jetting was rich from before.

[dober250R]

I wouldn't run it.... Way to much maintence with U4. You have to drain it after everytime you use it. Or it will eat up your seals. Even if it's free, I wouldn't run it.

[Nick110]

Originally posted by dober250R
I wouldn't run it.... Way to much maintence with U4. You have to drain it after everytime you use it. Or it will eat up your seals. Even if it's free, I wouldn't run it.

Im not worried about the maintence. I already drained the carb last night cause the team mechanic told me about the carb and seal thing.