'04 400ex WHAT NEXT???????

[premiumtommy]

I have a '04 400ex with a yoshi rs3 comp full exhaust, dynojet kit, K&N w/ precharger. My question is, what should I go for next. I am not gonna go crazy, like bore kits, pistons & such? But alittle more go is what i want.

Should I get a carb? If so, what are my options?
Should I get cams? If so, what stage is suited best for a mostly stock engine & again, what brands are best?

This addition will most likely be the end of my modding to the quad as I have many other toys that need attention.

If it matters, I weigh about 190 w/ gear and I'm located in CT at roughly 200-1400 ft ASL. Oh, I use 93 octane.....

I appreciate the help. Thanks

[alaskin 450R]

for the carb situation, i would go for a edlebroch carb, they are spendy. i just got done ordering a 450R carb for my 400,

to answer your cam question its all about what kind of power you want. if you want low end power i would go for a stage 1, for mid and top end i would go for a stage 2, i have a hot cam stage 2.
but if you install a cam you want to get a high performance piston to go with it. you will feel alot more power with the high perf. piston.

[blakefoote]

Originally posted by premiumtommy
I have a '04 400ex with a yoshi rs3 comp full exhaust, dynojet kit, K&N w/ precharger. My question is, what should I go for next. I am not gonna go crazy, like bore kits, pistons & such? But alittle more go is what i want.

Should I get a carb? If so, what are my options?
Should I get cams? If so, what stage is suited best for a mostly stock engine & again, what brands are best?

This addition will most likely be the end of my modding to the quad as I have many other toys that need attention.

If it matters, I weigh about 190 w/ gear and I'm located in CT at roughly 200-1400 ft ASL. Oh, I use 93 octane.....

I appreciate the help. Thanks

ide go with a cam!!! i have a stage 2 hotcam and love it!3

[josiah400ex]

Originally posted by blakefoote
ide go with a cam!!! i have a stage 2 hotcam and love it!3

did you replace the piston too.....

[premiumtommy]

would be getting a 450r stock carb the same as a Edelbrock aftermarket for the 400ex?

with the carb and a stage 2 cam, would i be setting the engine up for failure if i didnt start doing pistons and gaskets?

like i said. i dont wanna go to far with this engine modding. the most i am willing to spend is another $400 and this should include at least new sprockets and chain.

thanks again. :)

[86GN]

If you haven't cut a hole in your air box lid do that.
I'd look into a cam. That will give you the most bang for the buck on a stock bore.

[blakefoote]

Originally posted by josiah400ex
did you replace the piston too.....

yeah...it will still help out some

[Old Head]

Originally posted by 86GN
If you haven't cut a hole in your air box lid do that.
I'd look into a cam. That will give you the most bang for the buck on a stock bore.


Why do people insist on destroying their air box lid when there is all the other options out there. Just take it off and get an outter wears for your filter. personally I still use my lid for when i wash my quad.

[blakefoote]

Originally posted by 86GN
If you haven't cut a hole in your air box lid do that.
I'd look into a cam. That will give you the most bang for the buck on a stock bore.

just take thelid off...lol

[parts eeter]

fatten the pilot and the main jet,and mod or remove your lid.You will notice a difference.If you want more still use a stock bore 10:1 wiseco piston and leave the stock cam in there.I think this is what you are looking for.Piston kit 86.00 from rocky mountain,gaskets,25.00,sprocket kit 70.00 bux from rocky mountain.Install free cuz I dont charge myself any labor!:D

[CHEVYZ]

Originally posted by premiumtommy
would be getting a 450r stock carb the same as a Edelbrock aftermarket for the 400ex?

with the carb and a stage 2 cam, would i be setting the engine up for failure if i didnt start doing pistons and gaskets?

like i said. i dont wanna go to far with this engine modding. the most i am willing to spend is another $400 and this should include at least new sprockets and chain.

thanks again. :) The edelbrock carb is better, but will cost much more. The Edelbrock will give you slightly better performance, and yet things like jets are not even a problem ( You don't use any).... not to mention no mods are necessary.

A piston would do well with the change, but it isn't exactly necessary. Your engine would still run well without one, but you would see more gains with one. The stock compression on a 400EX is relatively low. If you can do so, a piston and cam would be two great accesories ( Cam- stage 1 or 2 Hotcam would do nicely, your choice.... with stock bore I would go with a stage 1).

[04'400ex'er]

Just buy a $130 hotcam stg. 2 and remove your airbox lid at the same time. If you install it yourself, I guarentee it will be the most power per dollar you do to the quad. It will also be fine with your stock motor. They dont call it a "drop in" cam for nothing. This will put you at the power you are looking for.

[parts eeter]

You will lose all your torque and compression with a large duration cam,and if you dont make it up by a high comp piston it will prolly run like crapola.I used a 11:1 piston with a stage 1 cam.if I used a stage 2 I would have used a 12.5:1 to get back the low end.With longer duration the valves stay open longer and as a result can lower compression lbs and reduce power.Its a balancing act for sure.With mild builds a smaller cam is best for sure.