yz400f on race gas

i was just wandering if anyone is running race gas in their bikes, if so what r u running and what is it like in power and in price? :banghead::banghead:

i was just wandering if anyone is running race gas in their bikes, if so what r u running and what is it like in power and in price? :banghead::banghead:

Unless your engine is modified you won't feel any difference in running race fuel.

I run 60/40 race gas/91octaine and I would say I notice a difference in the bike. Took me a while to get it running right, but I like it an am gonna contunue to use it. And when I say difference I mean I just like the way it runs, its stronger and has more grunt in my book. I buy the 101 octaine stuff from Gas City for like 5$$ a gallon. It also smells awsome!!!! do a search, I know this has come up a few times before.

Race gas burns much cleaner and thus keeps your plug and engine very clean. There is not the additives that there is in the pump gas.

If you want to notice a difference in power, get the gas that is oxygenated. The U4 or old name of Ultimate 4 stuff comes to mind. We have the local MNOP place has 100 octane with 4% oxygen which is similar. Anyways the oxygenated fuel in the dyno on a stock 450 gave 4hp more.

No race gas is going to give you substantial gains without properly tuning the machine to the fuel and the atmosperic conditions.

Unless you plan on modfying the engine and tuning it to top performance, stick with pump swill. The Yamaha thumpers work just fine on it.

Using U4, or an equivalent, will give you 1-3 (maybe more) HP over pump gas IF you jet for it. However, as easy this "modification" is, it costs $8-10/gallon, and will continue to cost that much for as long as you use it.

OTOH, a set of cams, a good exhaust sytem, and correctly jetting for the combination on pump fuel will give you that much, and will cost money only once. So a pipe and cams would be something like $850, which is the price of roughly 18 cans of race gas. Just another way to look at it.

Using U4, or an equivalent, will give you 1-3 (maybe more) HP over pump gas IF you jet for it. However, as easy this "modification" is, it costs $8-10/gallon, and will continue to cost that much for as long as you use it.

OTOH, a set of cams, a good exhaust sytem, and correctly jetting for the combination on pump fuel will give you that much, and will cost money only once. So a pipe and cams would be something like $850, which is the price of roughly 18 cans of race gas. Just another way to look at it.

Grey thanks for the most honest realistic answer yet....I use VPU4 exclusively in my 450 and it does add power but it does cost.....some jetting tweaks are better (I use JD Jetting kit)but it will run ok with stock jetting. The octane is not higher so carb seals are not adversely affected - BUT you must drain all out of carb after each ride - it will cause vapor build up in the carb if left for extended periods of time

Anyways the oxygenated fuel in the dyno on a stock 450 gave 4hp more.

I'd like to see some proof.

I've been running race fuel for a while now. I ran it with the bike completely stock and still use it today. My fuel of choice is Citgo 110 leaded. A simple turn of the fuel screw was all my bike needed to carborate correctly. The bike starts easier, burns cleaner and definitely has more power from idle all the way to the rev-limiter. I never drain my carb after rides, and I have never had the fuel eat any seals from the carb. I have never compared dyno charts with the Citgo fuel, but I bet I gain close to 1 horsepower. The Citgo in southern Indiana costs $4.74 a gallon (not too bad considering pump fuel prices).

I'd like to see some proof.

then go buy some U4 and try it - you will never want pump gas again

50/50 for me.. only thing i get out of it is a nice crisp throttle response.. :banghead: i dont see any power gains other than the throttle response..

I wasnt too impressed with the VP/ultimate 4 over the 110 leaded I was running and it ate the oring in my petcock! The 110 never damaged anything. The power is not as important as consistency and crispness is.

then go buy some U4 and try it - you will never want pump gas again

Well that depends, how much horsepower does it give on a 250F? The same?

50/50 for me.. only thing i get out of it is a nice crisp throttle response.. :banghead: i dont see any power gains other than the throttle response..

It is ruined if diluted......

I wasnt too impressed with the VP/ultimate 4 over the 110 leaded I was running and it ate the oring in my petcock! The 110 never damaged anything. The power is not as important as consistency and crispness is.

Sorry U4 does not eat rubber. I have been using it since it came out 2.5yrs....your 110 however will eat rubber and carb seals.....proven over and over with C112

Well that depends, how much horsepower does it give on a 250F? The same?

Listen I am not trying to sell you all on this ... it works for me and that is all I care about....

On the 250 the HP increase is the close to the same....

Sorry U4 does not eat rubber. I have been using it since it came out 2.5yrs....your 110 however will eat rubber and carb seals.....proven over and over with C112

All I know is I ran 110 for a couple of years with no problem, ran Ultimate for less than 2 months and the seal on my petcock started leaking. Could be only coincidence but I will be going back to the 110 if only for the ease. :banghead: I always turn the gas off and run the engine til it dies so the carb soaking in either fuel is a non issue.

All I know is I ran 110 for a couple of years with no problem, ran Ultimate for less than 2 months and the seal on my petcock started leaking. Could be only coincidence but I will be going back to the 110 if only for the ease. :banghead: I always turn the gas off and run the engine til it dies so the carb soaking in either fuel is a non issue.

buy yourself some more orings - your gonna need them... :banghead:

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