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using race fuel in 450's?

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I was just thinking.. since the 450 is such a high compression motor at 12.0 : 1, isn't it pushing the stability of pump 93octane gasoline?

has anyone used 104 or higher octane fuel and with what results? i would think it could only improve performance. any imput?

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With the good combustion chamber and the three D ignition map, you dont need much more than about 98 MON. Pump 91-93 runs fine on C/R's to 13.5 on the CRF.

Race fuel may yield a little throttle responce and easier starting if you jet for it. But there's no real need or HP in traditional race fuels. Now if you run VP U4 or something else that has a really high O2 content, there's real hp to be had.

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I run 110 leaded, ill have to look at whats its called when I go get some more, mixed 50/50 with pump gas, it helped with my throttle response but I dont notice much in the way of hp but thats not the reason Im running it.

Im using it for the better throttle response and I was also told that leaded gas is better for valves. Downside is it 6.85 a gallon for me but its very easy for me to get. Plus Im a believer that 91, the highest I can get here, is not the best for the bike. Im may be wasting money but in my mind its worth it.

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With the good combustion chamber and the three D ignition map, you dont need much more than about 98 MON. Pump 91-93 runs fine on C/R's to 13.5 on the CRF.

Race fuel may yield a little throttle responce and easier starting if you jet for it. But there's no real need or HP in traditional race fuels. Now if you run VP U4 or something else that has a really high O2 content, there's real hp to be had.

I would run VP in my 250 w/ 13.5:1 compression and it ran like a champ!!!there was a major difference IMO between VP and 91 octane pump gas.

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Oxygenated fuel is the way too go. If yer gonna put anything other than pump.I personally like A sunoco fuel GT PLUS 104 octane and 4.8 % oxygenation..... :thumbsup:

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I run 110 leaded, ill have to look at whats its called when I go get some more, mixed 50/50 with pump gas, it helped with my throttle response but I dont notice much in the way of hp but thats not the reason Im running it.

Im using it for the better throttle response and I was also told that leaded gas is better for valves. Downside is it 6.85 a gallon for me but its very easy for me to get. Plus Im a believer that 91, the highest I can get here, is not the best for the bike. Im may be wasting money but in my mind its worth it.

I was wondering about the use of lead in these engines also. I know back in the day when valve seat material was crap, the lead in the fuel had a cushioning effect on the valve seats, and improved seal. As a side benefit I believe it also helps the octane rating. Unfortunately it also leaves a lot of deposits on stuff.

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hmmm.. i guess that would be a question for the jetting expert then huh? im so lost :thumbsup: when it comes to jetting and the procedures and stuff.. maybe i should orders james dean's book....

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I used to run VP U4, but then I broke ass college kid. But i do have to say I noticed a little difference. The response seemed to be a little bit crisper. But now I just run 93 pump gas, I guess it gets my bike around the track.

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Can I just run the VP U4 without re-jetting?

I'm running stock jetting in my 06 but I also have motor work and cam! It is also in the middle of the summer here 95 degrees and with the heat index around 110. My plug is a nice tan color! :thumbsup:

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