Sprockets to beat a 2007 Honda 400ex

[jerod400ex]

i am changin my sprockets i want to add more torque but not lose very much top speed wat size should i use...... i would like to change the sprockets so i can beat my buddys 07 400ex with hmf slip on and rejetted..... we top out and then he slowly creeps past me:skeptic:..... wat size i need to stop this prob????

[marioweldinginc]

A 13t on the front of a 99-04 significantly reduces top speed.

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[jerod400ex]

A 13t on the front of a 99-04 significantly reduces top speed.

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i dont want tht to happen..... if i was to do a 16t in the front and keep a 38t in the back and then buy a dyno jet kit would tht raise top speed significantly and the jet kit would restore lots of torque??

[marioweldinginc]

If you go 16/38 you would have all the top.speed you need. In fact you wouldnt have a good bottom end at all.

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[jerod400ex]

If you go 16/38 you would have all the top.speed you need. In fact you wouldnt have a good bottom end at all.

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would the dynojet kit help at all its suppose to add 15 to 25% horsepower..... i want to still have a pretty decent bottom end

[marioweldinginc]

I have a dynojet stage 2, whitebros slipon, k&n filter and EHS airbox lid and i prolly freed about 6 max rear wheel horsepower

Remember a company makes hp claims using perfect parameters not on the trails

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[marioweldinginc]

would the dynojet kit help at all its suppose to add 15 to 25% horsepower..... i want to still have a pretty decent bottom end

You should switch to a.free flowing exhaust (any slip on really) a free flowing intake or air filter

For stage two you need to open your airbox either by removing the lid or using an ehs kit

Then the dynojet kit will make hp. Without mods the jet kit wont do.much cept make your.wallet lighter

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[jerod400ex]

I have a dynojet stage 2, whitebros slipon, k&n filter and EHS airbox lid and i prolly freed about 6 max rear wheel horsepower

Remember a company makes hp claims using perfect parameters not on the trails

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ya i see wat ya mean.....and im talkin drags so i need to find a good combination so he wont just loose me off the start and in the end i will pull on past him

[jerod400ex]

You should switch to a.free flowing exhaust (any slip on really) a free flowing intake or air filter

For stage two you need to open your airbox either by removing the lid or using an ehs kit

Then the dynojet kit will make hp. Without mods the jet kit wont do.much cept make your.wallet lighter

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one tht blows out more air u mean than the white bros....... i was thinkin of buyin k&n air filter with an outerwear pre filter and then just cuttin the air box off and put in the jet kit

[marioweldinginc]

I have a wb and its not restrictive at all. But any slipon will flow more air than stock

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[jerod400ex]

I have a wb and its not restrictive at all. But any slipon will flow more air than stock

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ya i have a white bros on right now

[marioweldinginc]

You might just want to take the spark arrestor out but you would have to add more fuel. You might lean out the mixture too much and burn up your valves

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[jerod400ex]

You might just want to take the spark arrestor out but you would have to add more fuel. You might lean out the mixture too much and burn up your valves

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ha i dont want to be fixin things i want to improve lol..... ohh by the way i should mention the ex hasnt been rejetted since i put the white bros on

[marioweldinginc]

I would get as much of your add ons as possible then rejet. This way you dont have to rejet for every part you replace. But dont drive around hard without rejetting. The more air you flow the more fuel your going to need. Without the rejet you could do some damage to your atv. Also you can step up to a hotter sparkplug

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[jerod400ex]

I would get as much of your add ons as possible then rejet. This way you dont have to rejet for every part you replace. But dont drive around hard without rejetting. The more air you flow the more fuel your going to need. Without the rejet you could do some damage to your atv. Also you can step up to a hotter sparkplug

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wats a hotter spark plug gonna do??

[marioweldinginc]

Light off better with the mods you do.

an NGK DPR8Z is from the factory

Step up to a DPR9Z

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Edited January 3, 2012 by marioweldinginc

[jerod400ex]

k will it do anything else or just help make it easier to start

[rappy97]

It will melt a hole in your piston...

[jerod400ex]

uhh i dont want tht..... or r ya messin with me again lol

[rappy97]

No. Your lean already, which will eventually put a hole on your piston, but a hotter plug will make it worse.

[marioweldinginc]

which is the reason for the rejet

After all my mods I did, I also used a NGK D9 plug. Its tan in color so I must be doing something right

[rappy97]

which is the reason for the rejet

After all my mods I did, I also used a NGK D9 plug. Its tan in color so I must be doing something right

Did you learn that the tanish color on a plug is good from your Hanna Montana fan club? "you get the best of both worlds, lean or rich, no right in between"

Edited January 3, 2012 by rappy97

[marioweldinginc]

Im sorry what did you say?

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[rappy97]

Im sorry what did you say?

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[jerod400ex]

hey now ladies!!!!! calm down..... take a chill pill

[quadnut20]

I would get as much of your add ons as possible then rejet. This way you dont have to rejet for every part you replace. But dont drive around hard without rejetting. The more air you flow the more fuel your going to need. Without the rejet you could do some damage to your atv. Also you can step up to a hotter sparkplug

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Why would he want to run a hotter plug ?

[jerod400ex]

Why would he want to run a hotter plug ?

idk y i would want to do tht especialy if its gonna damage somethin:no:

[quadnut20]

I think all of you should take a chill pill !! you all are to starting to sound like a bunch of JR HIGH girls !!

[jerod400ex]

I think all of you should take a chill pill !! you all are to starting to sound like a bunch of JR HIGH girls !!

hahahaha u tell em:yes:

[quadnut20]

Jerod IMO Just stay with you current heat range and rejet :biggrin:Run it and check your plug and go from there !! I`ll bet CK 1999_400ex has the answer Your ex is stock with a slippon pipe I thought