2007 400 wont start after Dynojet kit

[jnapier5]

Here is the deal. I bought a DMC slip on pipe and the DynoJet kit and installed them last night per the direction with the kit. Everything went smoothly until i tried to fire up my beast. It will idle for about 10sec. then die. If i try and feather the throttle at all to keep it running it dies right away. I put the new needle on the 3rd notch and the 17o mian jet in as directed. The only thing that i did different was added a #42 slow main to the process but reading in this forum the 400 needs that # 42 to get ride of the cold start problems. Can anyone help me out here. I have a trip planed for friday and really want to see the improvemnt of the pipe.

[shawn3389]

i'm thinking the 170 dyno jet is to big of a main here's a link
http://www.exriders.com/vbb/showthread.php?s=&threadid=344906&highlight=dynojet

[ginobili07]

Did you mess around with the air/fuel mixture screw?

[jnapier5]

Nope nothing in the directions mentioned to.

[jnapier5]

Are you think more along the lines of a #160/ #165?

[ginobili07]

IDK about the jet size but i would try and mess around with the A/F screw mixture, i know when i rejetted my 02 it would start up either i had to screw in the A/F screw all the way then back it out 2 full turns and tinker with it a lil from there till it ran fine.

[jelrod05]

hi i have a 155 in mine and a 40 pilot jet and the air fuel screw out 3 turns from lightly seated and it runs aweosome.

[coryatver]

throw away the dyno junk and put in a 158 KEIHIN jet(lid on) or 165 lid off and 42 pilot and it will be good to go

[jnapier5]

So i can just use the #150 out of the Dyno then right since it shows = to the Kehein?
0,0640---- 165--------- 150--------- 140,6
Kehein Dyno MiKuni

[dariusld]

Originally posted by jnapier5
Nope nothing in the directions mentioned to.

The directions do mention it, but since you added a pilot jet your on your own. I didn't change my pilot jet and my bike starts and runs fine. If would of just installed the kit and followed directions you would be fine too. Do you know where the pilot screw is? Your going to have to mess with that to idle, if thats the problem.

[dariusld]

Originally posted by jnapier5
So i can just use the #150 out of the Dyno then right since it shows = to the Kehein?
0,0640---- 165--------- 150--------- 140,6
Kehein Dyno MiKuni

The main is not the problem.... yet. If it sputters when wide open then it will be a problem, but I had your same exact setup, except the your pilot jet, and ran good.

[jnapier5]

I know i'm going to sound like a tard but is Kehein and Mikuni the carb manufactures for Honda? I think i have the Mikuni if that isd the case. Which means the stock jet is already #148which equals a #158 Dyno. Just set me straight please.

[dariusld]

You have two choices. You can follow the directions and see if it still does it. Or you can mess with the pilot screw and see if it fixes it. Human error is also a possability.

[coryatver]

all 400's have keihin carbs. dynojets just don't work very good and are a pain to tune. send the kit or whatever back and get your money back and go to your local dealer and buy a couple keihin main jets there like 2 dollars each.

[dariusld]

Originally posted by coryatver
all dynojets just don't work very good and are a pain to tune. send the kit or whatever back and get your money back and go to your local dealer and buy a couple keihin main jets there like 2 dollars each.

I had no problem with mine, worked perfect just by following the directions.

[jnapier5]

my bad you are right it did say to adjust the air/fuel screw out 3.5 turns. so did that and did not work so took the carb off again and went to 2.5 turns and problem still there.

[dariusld]

You can adjust that screw with the carb on the bike. Just be very carefull to not get burned. Will the bike run if you rev it?

[jnapier5]

Nope as soon as i just barley touch the throddle it dies. like a hard shut down.

[dariusld]

If it was me I would throw the stock pilot jet back in and adjust the screw to 3 and see if it runs. And while your in there make sure you did everything right the first time. If it runs you can try to mess with the carb with the 42 after your trip.

[jnapier5]

I was thinking the same thing. I'll give it a shot.

[rideracelivemx7]

put the needle back in the stock location, eff the directions, 42 pilot and 170 are a great setting on a stock quad, you loose a little throttle reponse but oh well its worth the ponies, you can keep your lid on if you want to run stage 2 jetting, whcih is 170 main, 2.5 turns out on the fuel screw and stock needle, put your stock one back in if they gave you one and see how that helps, i ran stg2 jetting with stock exhaust and motor before my mods and it ran great.

[dariusld]

Your running no lid, right? Good luck

[dariusld]

Originally posted by rideracelivemx7
, put the needle back in the stock location, eff the directions.

What does this mean ?

[honda400ex2003]

If you went by the directions then 170 dj is wrong stage for your application. I ran a 138 dj with the needle on the third clip from the top with my slipon t-4 and a k and n filter. my kit did not even go up that high for the dj. I needed a 155dj and didn't have one. So lI switched to the keihin. I did not mess with the f/a screw but with the 42 which is big for a stock carb even for the cold starts it should be a 40 i believe but anyway try the f/a at 2 turns out and a 142 for the jet. if you are at sea level it should not be any different from that. I was am at about 800 ft. I would read the directions again. I am running a 170 keihin with my 416. that is a 155 in the dj. Otherwise put the stock pilot back in a go out 3 turns on the f/a and then mess with it seperately. Good luck, steve

[dariusld]

The directions do say "170".dynojet (http://www.dynojet.com/pdf/Q107.pdf)

[honda400ex2003]

check this out

400ex tuning and jetting (http://exriders.com/vbb/showthread.php?s=&threadid=344906)

4 pages of great jetting from people on here. good luck with it all, steve

[honda400ex2003]

quoted from the kit

stage 1

If you are running the stock exhaust use the DJ142 below 3000 feet,
DJ138 from 3000 to 6000 feet and DJ134 above 6000 feet. If you are
running an aftermarket exhaust, use the DJ146 below 3000 feet, DJ142

If you are
running an aftermarket exhaust, use the DJ146 below 3000 feet, DJ142
from 3000 to 6000 feet and DJ138 above 6000 feet.

stage 2

If you are
running an aftermarket exhaust, use the DJ170 below 3000 feet, DJ165
from 3000 to 6000 feet and DJ160 above 6000 feet.

stage 1 is the one to use
For mildly tuned machines using the stock airbox with stock or
aftermarket filter. May also be used with a good aftermarket
exhaust system.
stage 2 is really really rich for a stock motor I ran a 154 in my 416 with the lid off and it was lean. I needed a 155 and did not have one. good luck anyway steve

[dariusld]

A little rich is much better than a little lean especially in the desert heat.

[honda400ex2003]

But that is not just a little rich, its too rich to even run at this point. steve

[jnapier5]

So sounds like by me using the Dynojet 170 it is really a 190 on my Kehein carb. I think that is way to much for my stock bike. Great job on guessing that i'm in the derst also. It has been around 75 here in Mesa Az and will soon be really f-ing hot in the next month or so. So this is what i got out of this. I should change doen to a Dynojet #142 = 152 Kehein correect? 2 1/2 turns out. and possibly change my slow main back to the stcok#38. Now somewhere it says to put the stock needle back in but when i looked at the new nedle set at the 3 notch it was set at the same lenght. Nothing different in the needels is there as of a thinckness?

[jnapier5]

I just wanted to make sure that you guys kniow how much i appreciate all your help in this subject. I think that it is poeple like you all that make forums worth joining.

[honda400ex2003]

No prob on the help, that is why we are here. If you are running the dj use the dj needle it is shaped different to fit into the dj right the stock needle does not work because it does not fit good. you may not have a needle that adjusts for the stock needle. I think when they changed the carbs on the new ones, they changed the needles too. I hav the old one in mine so I can adjust it. When you check out the plug with a chop, it helps to keep it alittle rich. i would say move up one size after you get it perfect. That way you don't really have ot worry. Arizona has dry heat not humid heat most of the time, so it is not so bad. The humid stuff is when the motor gets really hot. Arizona cant get that cold anyway to need a 42 pilot. The cold starts on the 400 is for like below zero weather. I have the stock 38 in wisconsin and if I just pump it a couple of times it fires right up when it is 10 or 20 below zero. If you need any more help just ask. steve

[honda400ex2003]

heres some info on the plug chop you can do to check the plugs.

plug reading article (http://www.atvriders.com/articles/sparkplug.html)

I was looking up a search on "Plug Chopping" And I think this will help you....


plug chopping
the plug chop is an essential step in setting up jetting. not only does it help you get good performance, but more importantly, it helps you make sure yr bike is not running so lean that it will blow up!

1. wind it out! . warm the bike up well (5-10 min) with a new or fairly clean plug, correctly gapped, then wind the bike out in a gear. generally, i like to do this in 3d, but it depends how fast yr bike goes in each gear and where y'r doing this test (trying to run a bike out in 4th is not advisable in, say, a school zone). at least get into 2d.

2. hold it there ... even though you will be nervous, hold it in gear at max rpm for a while... what you are trying to do here is simulate the hardest use the bike will ever conceivably see. if you jet for the most stressful conditions, then yr normal use will be well within safe margins. keep yr hand on the clutch, as you could (doubt it, though) seize if you are jetted too lean to begin with. as always, use yr own judgment!

3. kill it. simultaneously hit the kill switch and pull in the clutch. hitting the kill stops the plug sparking; pulling the clutch stops the clutch from turning the engine over (bringing in more unburnt fuel). thus, you get a perfect picture of what the sparkplug looks like at the moment you hit the kill switch.

4. pull over, pull the plug out you will want to have gloves or a set of pliers, cause the plug will be fking hot!!!

5. read the plug. if the plug is:

black and wet: yr jetting is too rich

chocolate brown: yr jetting is right on! you kick ***!

white and burnt smelling: yr jetting is too lean! upjet now . you might also notice a blistered insulator. this is real bad. you are lucky you haven't hurt yr bike worse!

6. important note: heat grade of the plug will also affect the color the plug reads... if you use a 'cold' plug like an ngk b9, you will be more likely to get a richer plug reading. however, in my experience, plug grade --as long as you are within the normal spread of plugs, f.x. malossi 210s take between b7es and b9es -- is not terribly important when doing initial jetting setup. for finer tuning, plug choice does make a difference, however.


I did not thoroughly read this but I will get you really good info on how to read plugs. I jsut found it off another post. If you need extra help let me know. I will try my best. Good Luck Steve

[dariusld]

On forums you are going to have to learn who to listen to and who not to listen to. You didn't listen to me at all, so don't give me any credit. There at least 5 totally wrong info on this post. I would listen to Dynojet before anyone on the internet.

[honda400ex2003]

good luck with whatever you choose to do. I have never heard of a stock machine run anything of a 170dj. it is freaking huge. I dont even run that and I have a 416. I know others that run the exact same jettings as me with 416s too. Go thru the 4 pages of jetting and chek to see if anyone else is running anything that rediculusly big. I highly doubt it. but you can do whatever you want man. I am done you have all the info I am able to give from experience with mine. Pm me when you get it finished up so I can find out what you did. Good Luck, steve

[shawn3389]

yeah thats why i said the main was to big where he is at and what was done that 170dj main sounded to big to me....

[honda400ex2003]

Thank you, shawn3389. Steve

[shawn3389]

good post man i couldn't find the sheet that came with my dj kit

[honda400ex2003]

I dont have mine by me either, I did not walk out to the garage to get it. i don't even use the dynojets anymore since I did not have a 155 in my kit to get it where I needed it. I did not want to make it even a tad lean. I just know what they were I did it so many times to get it perfect with the dj. Good luck jnapier5. steve

[jnapier5]

Here is the exact copy of the Dynojet sheets that it comes with. Just because i saw you ask about them.



Q107.002
1999~2007 Honda 400EX
Stage 1&2
Stage 1
For mildly tuned machines using the stock airbox with stock or
aftermarket filter. May also be used with a good aftermarket
exhaust system.
Stage 2
For mildly tuned machines using the stock airbox with airbox lid removed,
using stock or aftermarket filter. Should also be used with a good
aftermarket exhaust system.
Parts List
1 Main Jet DJ134
1 Main Jet DJ138
1 Main Jet DJ142
1 Main Jet DJ146
1 Main Jet DJ150
1 Main Jet DJ155
1 Main Jet DJ160
1 Main Jet DJ165
1 Main Jet DJ170
1 Main Jet Adapter DJA001
1 Fuel Needle DNO190
1 Mixture Screw Tool DT008
1 Adjusting Washer DW0001
1 E-Clip DE0001
STAGE ONE INSTRUCTIONS
1. Remove top carb plate. Remove the slide lift arm screw and the two
needle plate screws. Flip the linkage forward and remove the slide
(Fig. A).
2. Install Dynojet needle on groove# 3 for applications below 5000 feet,
groove #2 for above 5000 feet, using all stock spacers. Install the Dynojet
washer above the E-clip.
3. Remove stock main jet. Replace with the Dynojet Main Jet Adapter
(DJA001). Screw the Dynojet main jet provided into the Main Jet Adapter.
If you are running the stock exhaust use the DJ142 below 3000 feet,
DJ138 from 3000 to 6000 feet and DJ134 above 6000 feet. If you are
running an aftermarket exhaust, use the DJ146 below 3000 feet, DJ142
from 3000 to 6000 feet and DJ138 above 6000 feet. Be sure that the jet
you are changing is the main jet.
4. Locate the Fuel Mixture Screw (Fig.B). For 2005 models ONLY use the
tool provided (DT008) to adjust the mixture screw. For 1999-2004
models, use a flat blade screwdriver. Turn the mixture screw clockwise
until it seats, then turn out 3.5 turns below 5000 feet or 3 above 5000 feet
STAGE TWO INSTRUCTIONS
1. Remove the airbox lid.
2. Remove top carb plate. Remove the slide lift arm screw and the two
needle plate screws. Flip the linkage forward and remove the slide
(Fig. A).
3. Install Dynojet needle on groove# 3 for applications below 5000 feet,
groove #2 for above 5000 feet, using all stock spacers. Install the Dynojet
washer above the E-clip.
4. Remove stock main jet. Replace with the Dynojet Main Jet Adapter
(DJA001). Screw the Dynojet main jet provided into the Main Jet Adapter.
If you are running the stock exhaust use the DJ165 below 3000 feet,
DJ160 from 3000 to 6000 feet and DJ155 above 6000 feet. If you are
running an aftermarket exhaust, use the DJ170 below 3000 feet, DJ165
from 3000 to 6000 feet and DJ160 above 6000 feet. Be sure that the jet
you are changing is the main jet.
5.Locate the Fuel Mixture Screw (Fig.B). For 2005 models ONLY use the
tool provided (DT008) to adjust the mixture screw. For 1999-2004
models, use a flat blade screwdriver. Turn the mixture screw clockwise
until it seats, then turn out 3.5 turns below 5000 feet or 3 above 5000 feet.

[honda400ex2003]

It may have been a 154 id needed to be the same as the 170 I have now. I got jipped on mine anyway I didn't ahve the 155 either when I called tehm to get one it would have been as much to ship the one i needed as the three jets I bought in town that were keihin. So i switched my needle and jet and put it back together. All well there. Thanks for showing yours. I did not nearly as many jets as you did. steve

[jnapier5]

Ya i for sure got a butt load of jets in this kit. I will let you all know what ahppened tomorrow moring. Crossing my fingers.

[honda400ex2003]

sounds great good luck, steve

[shawn3389]

yeah good luck hope it works out for ya

[ngates788]

Originally posted by jnapier5
Here is the exact copy of the Dynojet sheets that it comes with. Just because i saw you ask about them.



Q107.002
1999~2007 Honda 400EX
Stage 1&2
Stage 1
For mildly tuned machines using the stock airbox with stock or
aftermarket filter. May also be used with a good aftermarket
exhaust system.
Stage 2
For mildly tuned machines using the stock airbox with airbox lid removed,
using stock or aftermarket filter. Should also be used with a good
aftermarket exhaust system.
Parts List
1 Main Jet DJ134
1 Main Jet DJ138
1 Main Jet DJ142
1 Main Jet DJ146
1 Main Jet DJ150
1 Main Jet DJ155
1 Main Jet DJ160
1 Main Jet DJ165
1 Main Jet DJ170
1 Main Jet Adapter DJA001
1 Fuel Needle DNO190
1 Mixture Screw Tool DT008
1 Adjusting Washer DW0001
1 E-Clip DE0001
STAGE ONE INSTRUCTIONS
1. Remove top carb plate. Remove the slide lift arm screw and the two
needle plate screws. Flip the linkage forward and remove the slide
(Fig. A).
2. Install Dynojet needle on groove# 3 for applications below 5000 feet,
groove #2 for above 5000 feet, using all stock spacers. Install the Dynojet
washer above the E-clip.
3. Remove stock main jet. Replace with the Dynojet Main Jet Adapter
(DJA001). Screw the Dynojet main jet provided into the Main Jet Adapter.
If you are running the stock exhaust use the DJ142 below 3000 feet,
DJ138 from 3000 to 6000 feet and DJ134 above 6000 feet. If you are
running an aftermarket exhaust, use the DJ146 below 3000 feet, DJ142
from 3000 to 6000 feet and DJ138 above 6000 feet. Be sure that the jet
you are changing is the main jet.
4. Locate the Fuel Mixture Screw (Fig.B). For 2005 models ONLY use the
tool provided (DT008) to adjust the mixture screw. For 1999-2004
models, use a flat blade screwdriver. Turn the mixture screw clockwise
until it seats, then turn out 3.5 turns below 5000 feet or 3 above 5000 feet
STAGE TWO INSTRUCTIONS
1. Remove the airbox lid.
2. Remove top carb plate. Remove the slide lift arm screw and the two
needle plate screws. Flip the linkage forward and remove the slide
(Fig. A).
3. Install Dynojet needle on groove# 3 for applications below 5000 feet,
groove #2 for above 5000 feet, using all stock spacers. Install the Dynojet
washer above the E-clip.
4. Remove stock main jet. Replace with the Dynojet Main Jet Adapter
(DJA001). Screw the Dynojet main jet provided into the Main Jet Adapter.
If you are running the stock exhaust use the DJ165 below 3000 feet,
DJ160 from 3000 to 6000 feet and DJ155 above 6000 feet. If you are
running an aftermarket exhaust, use the DJ170 below 3000 feet, DJ165
from 3000 to 6000 feet and DJ160 above 6000 feet. Be sure that the jet
you are changing is the main jet.
5.Locate the Fuel Mixture Screw (Fig.B). For 2005 models ONLY use the
tool provided (DT008) to adjust the mixture screw. For 1999-2004
models, use a flat blade screwdriver. Turn the mixture screw clockwise
until it seats, then turn out 3.5 turns below 5000 feet or 3 above 5000 feet.

thats identical to the kit i got ...

[gojk]

Not to be a smart @$$, but do you have the gas turned on and gas in the tank? Sounds like you ran the gas out of the carb and the machine is starving for gas.

[honda400ex2003]

Hey can you guys describe the fuel air adjuster that comes in the kit. I got jipped on that too it looks like. Man your kit has alot of nice stuff in it compared to mine. I can't believe they changed them like that. Mine is about 5-6 years old now. That sucks. I will have to try to find an adjuster. It would make it easy to mess with. Steve

[ginobili07]

Originally posted by gojk
Not to be a smart @$$, but do you have the gas turned on and gas in the tank? Sounds like you ran the gas out of the carb and the machine is starving for gas.

x2 ive done it before or left the kill switch on :rolleyes:

[ngates788]

Originally posted by honda400ex2003
Hey can you guys describe the fuel air adjuster that comes in the kit. I got jipped on that too it looks like. Man your kit has alot of nice stuff in it compared to mine. I can't believe they changed them like that. Mine is about 5-6 years old now. That sucks. I will have to try to find an adjuster. It would make it easy to mess with. Steve
the only f/a mixture adjuster i got was for the 05- and newer.. all it is, is a little thing in the shape of a D for the older models they just tell you to use a flat blade scewdriver

[honda400ex2003]

Did you get it done today?? I am curious now. I had to go out and play around with mine today. I started to repack my exhaust and I changed the oil. Cold and snow are starting to get old. It was -8 degrees here again this morning. And theres still 5-6" of snow on the ground. Be happy you are in the desert. Steve

[honda400ex2003]

anything bro?? just figured I would check in to see how it came out. steve

[bigbad400]

they do tell you specificaly that you should not mess with the pilot jet when doing the kit, your idle would not have bean changed by putting on a exhaust, i have yet to change pilot besides when i removed choke, put you pilot back so you can get it to idle, then mess around with the mains till you get it to run right.

[dave4881]

Originally posted by jnapier5
Are you think more along the lines of a #160/ #165?

I run a Keihin 165 mainjet on one 400ex and a Keihin 162 mainjet on the other. Both run extremely well. I think the 170 DJ is too big. See the conversion chart at the beginning of this thread.

Your bike is not idling correctly so it shouldn't have too much to do with the mainjet not being correct. Close your fuel (mixture) screw and then turn it out 2 full turns. Start it up and check the idle again. If not, you may have to take the carb apart again and recheck everything. Make sure it is clean.

[droppedmazda]

i have 170 dj in mine and it runs great. i didn't change the pilot jet so i would say put your stock pilot back in and follow the directions exactly and it should run fine.

[honda400ex2003]

Still haven't heard if he did anything. This started last week and he said he was going to work on it a few days ago. If he goes back to the stock pilot and then goes to a 170 at least it will start and run I would still suspect it is alittle rich for his application. I would stick with going to about a 140 or 142 to get it close but to each his own. I hope he lets us know soon to see what he ended up with. Steve

[dariusld]

Originally posted by honda400ex2003
If he goes back to the stock pilot and then goes to a 170 at least it will start and run

How do you know that?

[bigbad400]

he knows that because the main is not in use at idle, the pilot and the needle are only used until you hit the throttle. i suggested to do the same, as i have saw this problem over and over again, like i said the directions in the kit tell you not to touch the pilot until the main is dialed cus your air fuel screw will be good enough to get it to idle. most common error in jetting ive seen yet. mine has a 42 pilot only cuz i have no choke and it gets below 0 in michigan, in the summer i set it back to stock and runs just like the 42 in the cold. 170 is prolly to big thow, for the application, its not a big bore. its just a slip on pipe. when he feathered the gas it died and when he started it it would idle for a sec then die, too much gas. you choking it out.

[bigbad400]

i just realized this guy is from arizona, why would you be worried about cold starts? like i said i live in michigan were it gets below 0 most of the winter months, and i never had a problem starting it with the choke, i removed it for the gains but thats the only reason i use a 42 pilot, in arizona you should not need to do that. in the summer with no choke average temp around 70 mine starts with the stock jet, easily, pump gas 3 times hit botton fires and dies, hit gas twice fires and idles, EVERY time. this 42 pilot thing is way misunderstood. if you have a choke you should not need a 42 unless you live in like alaska riding in -25 weather.

[honda400ex2003]

It should start up at least and idle. It will still be too rich though. Putting the stock pilot back in it should run better on start up and even alittle better when the needle starts to lift. It may still be rich there too but it should be closer. I still say to start with the 142 or so. steve

[dariusld]

Originally posted by bigbad400
he knows

He only knows what the guy has said on here, he is not sitting infront of the bike. So he doesn't KNOW. So if something else is wrong, that he hasn't told us, will it still start?

[honda400ex2003]

Should unless that happens!! WOW. Thanks bigbad400, he has just been going around and around with me on this thread. I really don't care too much, just wanted to help jnapier out alittle bit I have went through this before with my kit so I figured I would mention what I have had mine at to get it perfect where I am. Steve

[honda400ex2003]

I hope Jnapier has it running right. Still have not heard what he finished at or if he even has it running. steve