jerod400ex

Sprockets to beat a 2007 Honda 400ex

33 posts in this topic

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????

Share this post


Link to post
Share on other sites


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

Sent from my SGH-T959V using Tapatalk

Share this post


Link to post
Share on other sites
A 13t on the front of a 99-04 significantly reduces top speed.

Sent from my SGH-T959V using Tapatalk

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??

Share this post


Link to post
Share on other sites

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.

Sent from my SGH-T959V using Tapatalk

Share this post


Link to post
Share on other sites
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.

Sent from my SGH-T959V using Tapatalk

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

Share this post


Link to post
Share on other sites

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

Sent from my SGH-T959V using Tapatalk

Share this post


Link to post
Share on other sites
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

Sent from my SGH-T959V using Tapatalk

Share this post


Link to post
Share on other sites
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

Sent from my SGH-T959V using Tapatalk

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

Share this post


Link to post
Share on other sites
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

Sent from my SGH-T959V using Tapatalk

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

Share this post


Link to post
Share on other sites

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

Sent from my SGH-T959V using Tapatalk

Share this post


Link to post
Share on other sites
I have a wb and its not restrictive at all. But any slipon will flow more air than stock

Sent from my SGH-T959V using Tapatalk

ya i have a white bros on right now

:yes:

Share this post


Link to post
Share on other sites

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

Sent from my SGH-T959V using Tapatalk

Share this post


Link to post
Share on other sites
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

Sent from my SGH-T959V using Tapatalk

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

Share this post


Link to post
Share on other sites

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

Sent from my SGH-T959V using Tapatalk

Share this post


Link to post
Share on other sites
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

Sent from my SGH-T959V using Tapatalk

wats a hotter spark plug gonna do??

Share this post


Link to post
Share on other sites

Light off better with the mods you do.

an NGK DPR8Z is from the factory

Step up to a DPR9Z

Sent from my SGH-T959V using Tapatalk

Edited by marioweldinginc

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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 :)

Share this post


Link to post
Share on other sites
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 by rappy97

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now

  • Similar Content

    • By sloundez
      Does anyone out there know where I can get a functional pair of wheel cylinders for subject ATV? Any suggestions welcomed. Thanks
    • By marcuslachance
      I
      I bought a Honda 250sx 1986 but the exhaust is broken. Apparently it's not possible to order a new one. I checked to order one on others compagny but there's noting.
      Do you know which exhaust it's possible to install. Is there a company who sold an exaust to fit on my 250sx.
      Sorry for my english
      Thank you
      Marc
    • By Npeters
      Im working on a old 1987 honda 125 4 wheeler in the school shop. It will start by getting pulled by another 4 wheeler but wont start with the pull start or Electric Start. When you pull start it it tries to start but when you try the electric start it just turns over but doesnt even act like it wants to start. The spark plug is dry and it shoots fuel out of the back(air filter side) of the carb. Weve had the carb off twice and it is complety clean. What are some things we can try?
    • By JenWal85
      Hope someone can help with this one.
      We took our 1984 Honda TRX 200 to the shop and they had it for about 2 weeks before they finally called and said that they had cleaned the carb and changed the battery and that it had started up.
      We went and got it and when we got home it would not start so we called them, they said bring it back in, so we did. They called us the next day and said they changed the spark plug, and that it was running. We went and got it again and it ran when we drove it off the truck.
      We parked it for about an hour because we were going to get ready to go on a ride. Well, it wouldnt start again.
      So we called them and they said the last thing they could do was order a new CDI box and put that on. I decided to just buy it myself, so I didnt have to pay them labor again. We put the new one on today and its still not starting.
      Does anyone have any ideas on what we could check to see what in the world is going on with this thing?
      Please and Thank you
    • By cprservices
      Does anyone on here have a 2013 honda rancher? I have had several Honda ranchers in the past but I bought this 2013 rancher and it hits the rev limiter at half throttle. It is very annoying and I was wondering if anyone else's Rancher does this. If this is something from the factory or if I have a problem or not just trying to figure it out. Any help would be appreciated