Jeting Question

[TGW_400ex]

OK I put a pipe and K&N on my 400ex and my friend insists that its doesnt have anymore power until u jet it (even tho i really dont think i needs jetted) and I think hes full of it what do u guys think?

[JOEX]

Supposedly the 400 comes lean from the factory. I have no proof of this, just what I have heard.
Adding a high flow filter and pipe will only and to the lean-ness.
Throw in a 155 main and maybe a 40 or 42 pilot to aid in starting then ride the mofo:)

Joe

[TGW_400ex]

Originally posted by JOEX
Supposedly the 400 comes lean from the factory. I have no proof of this, just what I have heard.
Adding a high flow filter and pipe will only and to the lean-ness.
Throw in a 155 main and maybe a 40 or 42 pilot to aid in starting then ride the mofo:)

Joe
This wasnt my question tho my question was would a 400ex gain power if u added a pipe and airfilter w/o jettin

[UglyMotha™]

yes a properly jetted piped ex will have more power then an un-properly jetted piped ex


does that answer your question, jetting can make or break a bike it is that important and any time you fooling with air flow in and out of a the motor that is goin to involve playing with the jetting

[TGW_400ex]

That sorta answers it but i really want to know would a piped 400ex w/ a K&N and no jettin be faster than a stock one

[chrisp333]

maybe, if you want to blow your bike up trying:blah:

[TGW_400ex]

ok i give up

[UglyMotha™]

no it can actually be slower cause your leaning the motor out so much that it goin to run hotter and with heat you loose power it's all about the right air to fuel ratio that like asking if i up the water ratio to air ratio from .02% all the way to 50% are you going to drown when you breath or be able to run faster a motor works the same way to much air and too little fuel will kill your motor when you add a filter and a pipe you letting more air flow in and out of your motor and you need to compensate with the fuel or else it's not goin to run at it's peak performance

[Out_Sider]

it would be stupid to put a pipe, and filter on without jetting!!!!! those things dont go together!!! put a 155 in it.

[TGW_400ex]

Originally posted by JOEX
Supposedly the 400 comes lean from the factory. I have no proof of this, just what I have heard.
Adding a high flow filter and pipe will only and to the lean-ness.
Throw in a 155 main and maybe a 40 or 42 pilot to aid in starting then ride the mofo:)

Joe

Huh in the book it says they come a lil rich not lean?:huh

[TGW_400ex]

What jets would u recomend to run if u have a pro circut T-4 and a K&N then

[JOEX]

Just trying to help out......:rolleyes:
Like I said, I was going by what I have heard. What book are you going by?

You may gain more power but the gearing is what determines speed. Modding the motor only gets you to the top speed faster. I'm sure there are some nuances of the air/fuel mixture like Ugly stated but it is the gearing that really makes the top speed change.

If you don't want to hear someone elses advice or opinion don't ask any questions.

Joe

[chrisp333]

with a t4 and a k&n i would prob run a 155 main or so. i m pretty sure it comes from the factory a little lean. dont quote me but the EPA are up these atv comps azzes when it comes to emmissions. what you do with it after you get it is up to you and the aftermarket comps are all about more air in and out they dont care about emmissions.

[cals400ex]

Originally posted by JOEX
Just trying to help out......:rolleyes:
Like I said, I was going by what I have heard. What book are you going by?

You may gain more power but the gearing is what determines speed. Modding the motor only gets you to the top speed faster. I'm sure there are some nuances of the air/fuel mixture like Ugly stated but it is the gearing that really makes the top speed change.

If you don't want to hear someone elses advice or opinion don't ask any questions.

Joe


i want to know the same question as joe, what book you going by??? i know it sure as he!! wasn't the owners manual. look at page 143 in the owners manual. they are jetted lean for emissions from the factory. running a bike lean makes it get hotter than normal. to answer your question will a bike gain power from a pipe/filter combo after being jetted? YES it will. it won't be 10 horsepower or anything but it would be noticable if you were racing another stock bike. if you didn't jet it correctly, i am betting you would be about the same speed as a stock one. try a 155 keihin main jet.