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400excaleb
10-15-2006, 05:22 PM
ok last year i was running a 165main jet in my 2005 400ex with full hmf and uni filter. i was running rich but not much. then i rode it all winter then in spring it started running lean, the i changed the jet up to a 170 and it was black went back to the 165 and black and ended up putting stock jet needle and fuel mixture screw at 2 turns out and it is running rich. i havnt changed nothing but that so what could this be
johnsls
10-15-2006, 06:22 PM
Not for nothin but ,, What color should the plug be?

Mines black too,, I've got a 170 jet & 42 piolet.. 2 1/2 turns out.

I was thinking the plug looked good but was coming on here to ask..
Any motorheads out there?
Rancher2005
10-15-2006, 07:36 PM
roughly it should be the color of a brown paper bag...roughly
johnsls
10-16-2006, 07:05 AM
So what does it mean if it roughly black in color?
More like the end of your exhaust or muffler exit.
Roman
10-16-2006, 07:10 AM
It means that "somewhere" in your jetting your too rich.
johnsls
10-16-2006, 07:23 AM
So if I'm 2 1 /2 turns out what do I do? Go out to 3 or back in to 2 turns out???
Roman
10-16-2006, 12:18 PM
If you know your rich on the pilot circuit then go to two out, however you may be rich somewhere else. Main, needle, needle clip. You need to take all of these into account.
Eviltanker
10-16-2006, 02:40 PM
Dude, don't worry about running the factory jets. some Wheelers run that way, Mine does just needed to tune the mid range.
400excaleb
10-16-2006, 02:59 PM
Originally posted by Eviltanker
Dude, don't worry about running the factory jets. some Wheelers run that way, Mine does just needed to tune the mid range.
i got a dyno jet kit but i put the carb back to factor cause i couldnt get the jetting right, and see what i could do from there. but when i seen it was rich there i thought maybe something was wrong.
cals400ex
10-16-2006, 04:19 PM
ok ok ok.....so your plug is black right? was that after a plug chop or just after randomly taking your plug out? if your plug is pretty black then you very well could be rich on one of the circuits. however, which circuit is it? you could be rich on the slow circuit and as lean as heck with the mainjet. you see my point? so you need to check your idle circuit, your needle clip, and your mainjet. also, dynojets and keihin jets are different. so a 165 dynojet does NOT equal a 165 keihin jet. this is another thing to consider when jetting. plus, the stock keihin needle and the dyno jet needle are different as well.
400excaleb
10-17-2006, 02:44 PM
Originally posted by cals400ex
ok ok ok.....so your plug is black right? was that after a plug chop or just after randomly taking your plug out? if your plug is pretty black then you very well could be rich on one of the circuits. however, which circuit is it? you could be rich on the slow circuit and as lean as heck with the mainjet. you see my point? so you need to check your idle circuit, your needle clip, and your mainjet. also, dynojets and keihin jets are different. so a 165 dynojet does NOT equal a 165 keihin jet. this is another thing to consider when jetting. plus, the stock keihin needle and the dyno jet needle are different as well.

i no about how the jets are different, so how do i check each circuit if it is rich or lean.