Stupid question but.…

[jake"08"400]

Before my upgrades my quad had more power as in mid range to top end. Now I can't keep the front end up for nothing after about 1/2 throttle so my question is does that sound rich are lean on the needle setting? Any help would be very appreciated I know it's another jetting question but I'm bored and at work and it's got me thinking. Lol O and my jetting is 160 main 42 pilot 2.5 out on fuel air and needle stock.

[honda400ex2003]

how modified is your air box lid?

i would say to go 155 instead of a 160 and see how it goes.

steve

[honda400ex2003]

do this for each circuit also.

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 your bike goes in each gear and where you're 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 hot!!!

5. read the plug. if the plug is:

black and wet: your jetting is too rich

chocolate brown: your jetting is right on!

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 your bike worse!
See sheets below for proper plug colors and pictures.

steve

[jake"08"400]

Not a lot just some uni filter elements 6 of them I was thinking it might be rich I just wanted to see what y'all carb guys thought lol. I was hoping you would reply. And I did the header weld grind and to my surprise there wasn't much there to be grinding.

[honda400ex2003]

im betting that it is rich enough to notice a bit now that it is getting warmer. that would be a good cold weather jetting.

steve

[honda400ex2003]

little test also, take the lid off and see how it does. you should see a fair increase in top end if it is running a bit rich. i would say if you want to leave the lid off most of the time, you could run it without and run the 160.

then for the winter, add the lid back on and you are all set.

;)

steve

[jake"08"400]

I took the lid off and it seemed to loose power kind of a bog deal when I got on it hard.

[honda400ex2003]

do a plug chop first then and see where you are at.

make sure it is a new plug and see how it looks after a couple of passes on it.

steve

[jake"08"400]

I have done I wide open throttle check and it was a lil black but overall it was a brown color. Sorry should have told you that before that's why I thought maybe the needle is to rich are lean on it. And I'm thinking the main is also rich cause of the above stated of the plug being a lil black.

[honda400ex2003]

drop it to a 158 and see how it does

then go to a 155 and see how it looks

you can drop to the 2nd notch and see how it does too compared to the 3rd. do it with both main jets in there and take the best one. i would do the mains first since it will lean out both the main and the needle slightly without moving it.

steve

[jake"08"400]

Ok il work on it tomorrow. Im telling you what if I had to do over I'd leave it stock lol…j/k

[honda400ex2003]

lol thats no fun lol

you seem to have alot of issues with your jetting though dont you.

once you get it dialed though, the 400 carb is pretty good for staying in the sweet spot most of the time.

steve

[jake"08"400]

Yea I been working on this for a while now off and on as much as I can between messing with my mustang and other stuff with my quad. And jetting by far sucks worse than anything. Also I cleaned my headers up had them all shiny. Went and rode my quad for bout 10 mins and they look just as bad as before I cleaned them so I'm thinking on wrapping them.