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post #1 of (permalink) Old 10-02-2008, 03:34 PM Thread Starter
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my 400ex carb needs to breath

i have a 400ex bored .40 over (1mm or 407 cc)11:1 compression namura piston
stage 2 hot cam
full bills pipe
uni filter
no air lid
full port polish
a 165 main jet
42.4 pilot
needle cip lowerd 1
and choke removed

with the way the cam runs its all top end power
i have it all set up to suck in air and blow out as easy as possible
now is there anything else i can do to the carb to make it breath better?
i dont have much money i just dont know if there is something i can take out to let the air flow better.
so please tell any other popular 400ex carb mods. (i just need it to breath a little more so i can get a 170 main jet in it because it runs a little lean as is)
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post #2 of (permalink) Old 10-13-2008, 05:57 PM
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400ex breathing issues

I noticed you have a uni air filter have you tried a K&N I know foam is better but if you absolutely need more air then you need a high flow paper air filter
post #3 of (permalink) Old 10-14-2008, 10:34 AM Thread Starter
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i have found that foam filters breath better than K&N

foam breaths much better trust me
i have done many dyno runs and just seeing how much ritcher the engine runs with the k&n

k&n claims the breath sooo good and they have "tests" to prove it

well all the tests i have seen compare them selves to paper (K&N are cloth) and yes k&n breath much better than paper but not foam

dont belive me go test it urself
but thanks
and i do run in pretty dusty stuff at some points and K&N just dont cut it when it comes to hard core dirt

Last edited by Mr_RPM; 10-14-2008 at 10:40 AM.
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post #4 of (permalink) Old 12-16-2008, 10:58 PM
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foam filter's such as twin air and uni have to research data on their website about the performance and filtration of their filters unlike k&n. I have never had a probley with k&n there good filters. they only way to getter better airflow now is to take off the airbox and install a clamp on air filters, but if you ride in water than this wouldnt be good. if your 400ex is barley lean then its not going to hurt it, they are one of the most reliable engines (you get more power if your a little lean than rich). try to find a dynojet needle, if your bike is back firing when you let of the gas then this needle will clear that up.
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post #5 of (permalink) Old 12-17-2008, 08:49 AM Thread Starter
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im way ahead of u on that stuff
i work as the top mechanic at one of lead dealers in michigan

i just wanted to know of any popular mods (i now know there is not now after some research time) such as a carb swap with a diff machine that has been done many times and proven to be better

trust me i got the air box completly off (direct filter to carb intake it was a small intake boot i bought to fit the air filter on right to the carb)

dyno jets do work but a waste of money u can get just of good if not better of a jetting useing diff sized jets from the carborator company and experimenting on what size works best

dyno jet cant know everymachine's mods and conditions
and dyno jets 50 dollars
when the other gets are like 5 dollars each
so buy 5 diff sizes and find the best one for 25 bucks

and i have the stock needle lowerd by one clip
i have found dyno jet needles dont do much more than just ajusting the clip on the stock needle.

people are sad for thinking K&N and DYNO jets are the best
THEY ARE SIMPLY ADVERTISED THE MOST
but if they work best for u then thats how ur machine is set up

Last edited by Mr_RPM; 12-17-2008 at 08:53 AM.
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post #6 of (permalink) Old 12-17-2008, 04:30 PM
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Quote:
Originally Posted by Mr_RPM View Post
im way ahead of u on that stuff
i work as the top mechanic at one of lead dealers in michigan
your not a head mechanic, you do not even know basic carburetor theory as i learned from your post in the banshee jetting post. you dont even know basic terminology about engines.

Quote:
Originally Posted by Mr_RPM View Post
dyno jets do work but a waste of money u can get just of good if not better of a jetting useing diff sized jets from the carborator company and experimenting on what size works best

dyno jet cant know everymachine's mods and conditions
and dyno jets 50 dollars
when the other gets are like 5 dollars each
so buy 5 diff sizes and find the best one for 25 bucks

and i have the stock needle lowerd by one clip
i have found dyno jet needles don't do much more than just adjusting the clip on the stock needle.
I said buy a dynojet needle (look up the part number), it has a different taper than a stock needle. the taper is made for engines that are modified, your stock needle is made for a mostly stock engine. Its worked for me on a couple different bikes, IMO its worth $5 to try the needle out. actually dynojet does know your bike, they have a sheet that is inside the box which you fill out all of your mods and give them a call and they will help you tune your carb to your setup. I will go on to say that in order to fine tune your carb for the best results your going to have to buy a few individual jets.

Quote:
Originally Posted by Mr_RPM View Post
people are sad for thinking K&N and DYNO jets are the best
THEY ARE SIMPLY ADVERTISED THE MOST
but if they work best for u then thats how ur machine is set up
Yea i wouldn't buy a dynojet kit personally, but for people who dont know how to tune a carburetor or want to learn it is a good kit. to clear this up, theres is no different between a dyno jet and any jet that you buy from a dealer, its just a package put together.
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post #7 of (permalink) Old 12-17-2008, 04:43 PM Thread Starter
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ok then your right
u know me and who i am and everything about me

u are just one of those people who knows all the fancy words
and has money to have the best stuff out there so no one can argue with ya

yep i have no clue at all

sorry for bothering you

=(
do u expect me to know everything on hand
and sorry for being too lazy to look it all up to 100% perfection

thanks for correcting everything wrong i said

i guess im not aloud to say any slang or be lazy with my posts (2 strokes have no headers, they are expansion chambers. do i care about how i say it
just as long as ppl know what im talkin about)

sled= snowmobile
now dont yell at me now
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post #8 of (permalink) Old 12-17-2008, 05:12 PM
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I don't have to know you, any ordinary backyard mechanic knows this stuff. I guess i know some fancy words for being eighteen years old, yes i have nice things because i work my ass off for them and take care of them. but i don't know how you came to the conclusion that i have the best things out there...all i said was that i like k&n filters over foam and they cost about the same, but if you say there the best i guess i will agree with you
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post #9 of (permalink) Old 03-10-2009, 06:23 AM
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chattare gratis

problemi msn 2009!rispondeteeeeeeeeeeeeee!! 10punti!!!?vi prego ditemi un sito dove posso scaricarlo
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ciao ciao
post #10 of (permalink) Old 01-06-2010, 09:49 PM
ema
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MR RpM and alpinestar54, you two don't have to fight over things. Calm down you, too. Anyway, MR Rpm, having long lasting, well-maintained and quality parts don't imply that the owner is filthy rich or so. You can get quality parts for very reasonable prices and the maintenance of those usually comes on your car's handbook. Internet searching always comes very handy on matters like these. Anyway, this Mr Gasket Carburetor Jet dealer may also help you on getting parts that you need to fix your carb's performance.
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