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vp ulitmate4,i gotta admit im shocked.....

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is the hp alititude corrected or altitude?

also, i might have you get me a couple gallons for sunday

dan

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Dan,

I was curious how your motor ran after getting it together- also, did Tom put motor together or just do the machine work? I was curious b/c he in the past hasn't used the Wiseco piston.

Thanks,

Brian

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tom just did the machine work. i put everything together and im still lookin to get jetting on up top. the motor is really strong, much more mid range a little more top.

dan

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Burned did you make any jetting changes?

yes,the a/f showed lean so i added in 2 sizes main jet.it didnt really pick up any more power.i think i could go a size or 2 more.

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yah,im really pleased with how its going.beside the terrible aroma of U4,its amazing stuff. :p

i just recieved the JE 13.5 to 1 piston today.so that goes in next week. :)

the new head i ordered is on back order.so ron's majic is delayed. :) ive got all the other head parts though. :D

as far as the jetting goes,i tried putting more main jet in.the power fell off.for whatever reason my bike has always wanted less main jet.could be my dynojet air fuel meter is just off from others.

i find my peak power and best overrev at 13.5-14.0.

other guys i have talked to seem to find it 12.8-13.3 or so.

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Some words of warning with U4. We use it around here for the mini's and roadbikes. According to VP you are supposed to see 6% increase in HP in a stock motor.

1. Don't store it in plastic, either can or tank. The plastic effects the fuel somehow and it won't run well. Store it in metal can's, fresher is better on race day.

2. Don't leave it in the bike. Drain the tank and flush through some pump gas to prevent the U4 from gumming up the carb.

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thats good advise, you might even want to start it on pump gas , I have seen corrosion in the ports on engines that dont get purged

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Some words of warning with U4....

1. Don't store it in plastic, either can or tank. The plastic effects the fuel somehow and it won't run well. Store it in metal can's, fresher is better on race day....

Good points. The problem with plastic is outgassing and putting the container in a warm area only makes matters worse. The "light ends" (hydrocarbons that boil at ambient temperatures) that help with easier starting, better throttle response, more power, etc, will evaporate into the atmosphere through the plastic, which is why you want to store this and other high performance fuels in sealed metal cans and keep them in a cool place if at all possible to maximize the fuel's useful life.

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how long can you wait before you need to drain the fuel? is it safe overnight or more like a week+ ? :):)

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Some words of warning with U4. We use it around here for the mini's and roadbikes. According to VP you are supposed to see 6% increase in HP in a stock motor.

1. Don't store it in plastic, either can or tank. The plastic effects the fuel somehow and it won't run well. Store it in metal can's, fresher is better on race day.

2. Don't leave it in the bike. Drain the tank and flush through some pump gas to prevent the U4 from gumming up the carb.

Why does U4 smell so similar to M-1 (VP's methanol)??? :)

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thats a good ? , because it has some of the same trates as methanol , like gummy residue , corrosion, needs to be jetted richer , that fuel might have some alky in it

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I ask, because I've run meth in the sand, but I've been at the races/MX track and smelled something very close to M-1 and figured someone was running jacked up fuel. Then I got clued into U4.

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U4 in the bike overnight is fine I'd say a week is the turning point. If you want to store the bike longer than a week drain the tank and carb bowl. Refill with some pump gas just so things don't dry out.

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