03 400ex jetting help hmf slip on

[brandon32689]

Hey guys, first off I just got my first quad a 03 400ex. I have had seadoos for a while and got tired of always fixing them and going threw 100 dollars of fuel in 3 hours. Well I got the quad cheap it has a k&n filter on it with the lid removed and a white bros slip on that was cracked n leaked it ran awsome tho. I first off changed oil and cleaned k&n and put a prefilter. Then I just got a new hmf comp series slip on. I checked the jet it had was a 160 but I think its a dynojet cause it could be removed with flathead or 7mm. So I found 160 dynojet means 177 of the keihin. I took it out and put a new plug. It starts up on first try every time so easy. And idles great so I took it out if runs great I get about 4 th gear n kill if pull plug its pretty white so I do it again n same thing. I cone back in and throw a 190 keihin jet in and go back out it runs just as good to me no backfiring or bogging. I pull plug n its still a little white. Idk if I should go higher. That's the highest in my kit. I just don't want to run to lean and am learning with all this. I live in west tx its hot most the time and were 2800 ft abouve sea level. Do you guys got any advice for me.

[01boneless]

go about a half a turn at a time on your a/f screw if you have to go more than 3 full turns from fully seated than go up a piliot what notch is you needle im guessing if you running a 190 and its lean you neddle it all the way lean you need to put it on tne 3rd notch and try it

[brandon32689]

I tried it again when I got home but could only do it at 2nd gear in alley n took a few pics it looks a little better I'm still unsure if I should go higher on the jet 190 seems night to me for being lightly modded.

http://i465.photobucket.com/albums/rr11/brandon3268921/SU1BRzEyNzkuanBn.jpg

http://i465.photobucket.com/albums/rr11/brandon3268921/SU1BRzEyNzQuanBn.jpg

http://i465.photobucket.com/albums/rr11/brandon3268921/SU1BRzEyNzguanBn-1.jpg

http://i465.photobucket.com/albums/rr11/brandon3268921/SU1BRzEyNjkuanBn.jpg

[brandon32689]

Originally posted by 01boneless
go about a half a turn at a time on your a/f screw if you have to go more than 3 full turns from fully seated than go up a piliot what notch is you needle im guessing if you running a 190 and its lean you neddle it all the way lean you need to put it on tne 3rd notch and try it

I'm not sure how to check all that yet man sorry. All I've dibs is the main jet so far. I meN this thing fires up great and runs great imo but I meN I've never owned one. I do have a infared thermometer if anyone knows like what temp max I should see.

[01boneless]

dude that plug is almost perfect just barley white go out about a 1/4 turn and ill bet you will be golden but still check you notch on the neddle 190 is very hight of a jet for a stock bike but if it works who cares lol like i said the plug looks great cardboard brown is always perfect if it pops a little on decel like i said go about 1/4 more of a turn on the a/f

[CJM]

Thats VERY rich for a mostly stock setup. You should be running closer to a 155 main.

But the plug does look very good. You may have a massive air leak of some kinda and by jetting it higher your correcting it possibly tho.

[brandon32689]

Originally posted by 01boneless
dude that plug is almost perfect just barley white go out about a 1/4 turn and ill bet you will be golden but still check you notch on the neddle 190 is very hight of a jet for a stock bike but if it works who cares lol like i said the plug looks great cardboard brown is always perfect if it pops a little on decel like i said go about 1/4 more of a turn on the a/f

Thanks man were us this screw you want me to turn? And go out a 1/4 if in ? Thanks for your help man. Ya but that is just at 2nd gear it was whiter in like 4th at full throttle just didn't have my phone out there to take pics.

[01boneless]

a temp gun isent going to help lol heres a pic for ya the a/f is the fuel screw and just to let you no a good set up would be like a 158-160 main 3 notch needle and 2.5-2.75 on the a/f whitch is weird you have a 190 unless its a dj jet to

[01boneless]

ohh and a 40 piliot with a choke removed a 42 piliot

[brandon32689]

Originally posted by CJM
Thats VERY rich for a mostly stock setup. You should be running closer to a 155 main.

But the plug does look very good. You may have a massive air leak of some kinda and by jetting it higher your correcting it possibly tho.

well i have checked for air leaks really good thee is just a tiny one right were it slips on and from what i have read it will be there sometimes but its just at idle if i give it gas it goes away, so i did not mess with it. The hmf recomends a 170 jet with there exhaust, but i do have the K&N and the lid removed off the box so i was thinking i might need a little higher also there testing was done at 900feet abouve sea level.

[01boneless]

tell ya what like cjm a 190 is way to rich but what i dont get is the plug is good it would be better if you just but a 155-160 main jets and a 42 piliot and me and cjm will get ya going also check the needle!!!

[brandon32689]

Originally posted by 01boneless
a temp gun isent going to help lol heres a pic for ya the a/f is the fuel screw and just to let you no a good set up would be like a 158-160 main 3 notch needle and 2.5-2.75 on the a/f whitch is weird you have a 190 unless its a dj jet to

i do not have to remove the fuel bowl to get to that needle to turn it out do i?

[brandon32689]

okay well the hmf jet kit i got does come with a 42 pilot as well, i just have not put it on and kinda think there may be one in there already this thing starts up so easy even after it sat for a week just one push of the button and its on. But i did not get no history of this thing so i am just leaning little at a time, i am not fimilar with the carb so kinda scared to dig all crazy into it ya know.

[01boneless]

http://www.exriders.com/vbb/showthread.php?s=&threadid=445695&highlight=jetting+placement



read that over come back ill be here as long as you need

[01boneless]

and dont be scared of the carb now what im thinking is you said you dont know much about it im wondering if it dosent have a bit of motor work since it did so good on a 190 because that plug should have been WAY to rich

[CJM]

The air/fuel screw is a small screw on the underside of the carb you can adjust with a small flathead. Its nearly impossible to do unless you take the carb off the bike.

As for the needled, remove the top cover, remove the 2 small screws inside (magnetic screwdrivers are gold!), pull up arm and pull needle. The 3rd notch from the flat part is usually where you would want it.

[brandon32689]

i actually have ran across that thread while searching before postind and did see that, i also see that it is at 1500 feet abouve sea level. Do you know of any threads or videos of actually going in the carb and doing what i need to do i am just unsure what clip you are talking about and things like that, do i have to remove the carb?

[01boneless]

just remove the bowl and carb and its all right there the needle it right inbetween the float IIRC . easy as pie mmm pie :devil:

[brandon32689]

It could have some work done to it i am not sure at all. I bought it from some guy that had it for like a month and got in a bind and needed cash he sold it to me for like 1300 bucks so i took it, put new tires all the way around, nerf bars, exhaust, breaks and prefilter and its looks and sounds good ill post a pic

http://i465.photobucket.com/albums/rr11/brandon3268921/SU1BRzEyNjEuanBn.jpg
http://i465.photobucket.com/albums/rr11/brandon3268921/SU1BRzEyNTkuanBn.jpg
http://i465.photobucket.com/albums/rr11/brandon3268921/SU1BRzEyNjAuanBn.jpg

[brandon32689]

Originally posted by 01boneless
just remove the bowl and carb and its all right there the needle it right inbetween the float IIRC . easy as pie mmm pie :devil:

is it hard to remove the carb from the quad what all is holding it on there? sucker scares me i just do now want to break it or run it lean or anything, i am messing with the heart of the motor lol. I am pretty mechaincal inclined tho i have put motors in seadoos and rebiuld those carbs and stuff like that but they are all mikuni and all 2 strokes that i have messed with.

[01boneless]

d** nice bike dude ok heres the final product lol

get the following and id say you will be close its what i run and works great (of corse sea level plays a factor but shouldent be off much)

158 main
2.5 turns out on a/f screw
3rd notch
40 piliot

i have a slip on pipe filter no lid and a 11:1 piston (whitch dosent affect jetting much or at all)

[01boneless]

and about tearing into the carb dude your best be would be buying a manual it will show step by step if you wain a while ill get you instuctions!

[brandon32689]

Originally posted by 01boneless
d** nice bike dude ok heres the final product lol

get the following and id say you will be close its what i run and works great (of corse sea level plays a factor but shouldent be off much)

158 main
2.5 turns out on a/f screw
3rd notch
40 piliot

i have a slip on pipe filter no lid and a 11:1 piston (whitch dosent affect jetting much or at all)

okay thanks man i am going to do some more reading to and looking for pics of stuff with people messing with the carb and how hard its going to be for me to remove it lol. i should get off work earley enough tomorrow to mess with it and tinker around. but cant get to the track till next weekend for some good straight aways luckily changing the main jet is simple as pie. so i should not order anything higher than what i got.

[brandon32689]

Originally posted by 01boneless
and about tearing into the carb dude your best be would be buying a manual it will show step by step if you wain a while ill get you instuctions!

awsome man ill scroll the threads and google for some more info if you do see anything send it my way. i apppreciate your help to man thanks. sorry for all the dumb questions and all im learning.

[01boneless]

http://www.atvriders.com/articles/jetting.html


and its cool dude i have my carb off now any way come back tomarrow and ill have some detailed pics for yaof the parts and removel

[brandon32689]

[QUOTE]Originally posted by 01boneless
http://www.atvriders.com/articles/jetting.html


and its cool dude i have my carb off now any way come back tomarrow and ill have some detailed pics for yaof the parts and removel [/QUOTE


Awsome dude your a life savor.

[brandon32689]

Also should I put the 42 pilot in while I have carb off.