I'd like to rejet my 2003 kdx200. does anyone know what the clip position, pilot jet, and main jet are on now. Its totaly stock. My dealer told me to run 40:1 instead of 32:1 because i told him i was fouling plugs. I know this probably won't work because of what i have read here. I saw the recomendation that fit my altitude and temp very good in the carb tuning, starting points section. I would like to do this but i want to make sure im not running to lean instead of rich before i do this and want to make sure this wont make it to lean after i do this. If i was running lean would there be black oily stuff on the exhaust tip, and would i be fouling plugs (when i take them out they are totally BLACK)thanx
what are the stock jets
- Thread starter android86
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Jackpiner57
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- Aug 11, 2002
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android86,
If you go to www.buykawasaki.com you can look at parts diagrams for your bike.
It lists the jets there. The ones that are not an option are the stock ones I suppose.
They are: Main jet #160
Pilot jet # 48
Jet needle # R1174K/2AFKQ
It sounds like your bike is running rich. They come that way from the factory.
Become a subscriber to this forum and you can do searches for all kinds of necessary info. It's cheap like $12.00 , and you will get more than $12.00 worth of knowledge!
If you go to www.buykawasaki.com you can look at parts diagrams for your bike.
It lists the jets there. The ones that are not an option are the stock ones I suppose.
They are: Main jet #160
Pilot jet # 48
Jet needle # R1174K/2AFKQ
It sounds like your bike is running rich. They come that way from the factory.
Become a subscriber to this forum and you can do searches for all kinds of necessary info. It's cheap like $12.00 , and you will get more than $12.00 worth of knowledge!
canyncarvr
~SPONSOR~
- Oct 14, 1999
- 4,005
- 0
Stuck to the top of this forum, the 'Every kdx rider should read...' thread links CDave's site. He has listed stock jetting for kdxs there. Also baseline jetting changes for different basic modifications.
You mention 'carb tuning' which is on CDave's site, so maybe you've been there. It tells you most everything you need to know.
Cdave's 'Just kdx' and this board, although hosted by the same folks, isn't the same place.
Chance of running too lean is certainly possible. Highly unlikely, though if you observe common sense in jetting.
Common sense is: Knowing what your starting point is, what you want to change. Observe plug condition and engine response to arrive at correct jetting for your situation.
Common sense is not: Putting a jet sequence in your bike based on what **someone tells you** on this board with no regard to why or check of the outcome in your situation.
You CAN have a plug that is black from a bike that is lean enough to stick under WOT operation...if the jetting is off far enough in just the right places.
It's not rocket science...but being informed, advised (not told) and doing your own jetting is the only way to go.
The recommendations on CDave's site are straightforward, correct and not anything that will get you into 'too lean' trouble (other mech problems notwithstanding).
As an example: A dealer (or anyone else) that tells you to change from 32:1 to 40:1 to 'lean out' your bike, and in an attempt to stop fouling plugs is at the very least completely, absolutely wrong.
For one thing, you are making the air/fuel mixture richer not leaner. Secondly, a plug fouling issue is much more likely air/fuel related than anything else.
There isn't anything wrong with 40:1 in the kdx in the large majority of cases. But it's air/fuel that's the problem...and that is resolved with proper jetting.
In many fewer words: 'It sounds like your bike is running rich.' ;)
(refer to asterisks inserted above!)
You mention 'carb tuning' which is on CDave's site, so maybe you've been there. It tells you most everything you need to know.
Cdave's 'Just kdx' and this board, although hosted by the same folks, isn't the same place.
Chance of running too lean is certainly possible. Highly unlikely, though if you observe common sense in jetting.
Common sense is: Knowing what your starting point is, what you want to change. Observe plug condition and engine response to arrive at correct jetting for your situation.
Common sense is not: Putting a jet sequence in your bike based on what **someone tells you** on this board with no regard to why or check of the outcome in your situation.
You CAN have a plug that is black from a bike that is lean enough to stick under WOT operation...if the jetting is off far enough in just the right places.
It's not rocket science...but being informed, advised (not told) and doing your own jetting is the only way to go.
The recommendations on CDave's site are straightforward, correct and not anything that will get you into 'too lean' trouble (other mech problems notwithstanding).
As an example: A dealer (or anyone else) that tells you to change from 32:1 to 40:1 to 'lean out' your bike, and in an attempt to stop fouling plugs is at the very least completely, absolutely wrong.
For one thing, you are making the air/fuel mixture richer not leaner. Secondly, a plug fouling issue is much more likely air/fuel related than anything else.
There isn't anything wrong with 40:1 in the kdx in the large majority of cases. But it's air/fuel that's the problem...and that is resolved with proper jetting.
In many fewer words: 'It sounds like your bike is running rich.' ;)
(refer to asterisks inserted above!)
Last edited:
- Thread starter
- #4
i messed around with the air screw a bit. I did what it said under carb tuning for the pilot circuit. It says go to the next leaner jet if you have to go more than 2 turns out from fully seated. My bike was set at like .8 turns out and the bike continued to increase in rpm's well after 5 turns. More like 6 or 7. Just to see what would happen i went back to where it was and turned it a few times and it really seemed to help. More power, and no more sputtering. It allowed me to rev higher where before the bike would sputter. I think this may be my problem. So how much do pilot jets cost and do you think i should go 2 leaner since im so far off?
thanx
thanx
canyncarvr
~SPONSOR~
- Oct 14, 1999
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I've bought pilots for $3.50...I've seen 'em for $6.50.
They don't go down by sequential numbers. They run (richer->leaner): 48-45-42-40-38-35
Not a requirement at all..but changing by one size at a time is safer...also gives you an idea of the progression of things. It's 'progression' you'll see when your bike begins running a bit 'off' as temps drop/rise or elevations change. You'll recognize that progression better maybe if you've gone through 1-size jet changes on initial setup.
The first jet to choose is the main. Always start with it.
re: setting the pilot.
Setting it to 'hi idle' is a starting point. Using throttle response is the 'fine tune' factor. If your bike is jetted correctly (and mechanically sound), you will experience no bog, buh-wah or hesitation when you crack the throttle under load at a relatively low speed say in 2nd gear.
Have fun!
They don't go down by sequential numbers. They run (richer->leaner): 48-45-42-40-38-35
Not a requirement at all..but changing by one size at a time is safer...also gives you an idea of the progression of things. It's 'progression' you'll see when your bike begins running a bit 'off' as temps drop/rise or elevations change. You'll recognize that progression better maybe if you've gone through 1-size jet changes on initial setup.
The first jet to choose is the main. Always start with it.
re: setting the pilot.
Setting it to 'hi idle' is a starting point. Using throttle response is the 'fine tune' factor. If your bike is jetted correctly (and mechanically sound), you will experience no bog, buh-wah or hesitation when you crack the throttle under load at a relatively low speed say in 2nd gear.
Have fun!
canyncarvr
~SPONSOR~
- Oct 14, 1999
- 4,005
- 0
Looking at a throttle opening graphic that shows the effects of the different circuits at different openings will show the main jet to be 'most effective' 3/4 to WOT. That doesn't mean it has NO effect in other areas.
Get far enough off on your main jet and it will effect idle characteristics and low-end response.
I'm not saying you're that far off...just that there is a sequence involved and the main comes first. It's set using a WOT plug chop test and observing the effect on a clean plug. The test is described on CDave's site.
You can get an idea of what you're looking at plug-wise (info courtesy of mr. rohrich) HERE!
Attached is a pic from wibby that shows a new plug after a WOT plug chop test has been done. The threads have been cut away so you can see the mixture ring better. It gives you an idea what you're looking for.
A longer run will get you a darker ring. Color of the insulator is not considered in this instance. You want the ring in the area indicated to be approximately 1mm in thickness/width. The one shown is somewhat wider than that.
Get far enough off on your main jet and it will effect idle characteristics and low-end response.
I'm not saying you're that far off...just that there is a sequence involved and the main comes first. It's set using a WOT plug chop test and observing the effect on a clean plug. The test is described on CDave's site.
You can get an idea of what you're looking at plug-wise (info courtesy of mr. rohrich) HERE!
Attached is a pic from wibby that shows a new plug after a WOT plug chop test has been done. The threads have been cut away so you can see the mixture ring better. It gives you an idea what you're looking for.
A longer run will get you a darker ring. Color of the insulator is not considered in this instance. You want the ring in the area indicated to be approximately 1mm in thickness/width. The one shown is somewhat wider than that.
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- Thread starter
- #8
ok i did the main jet plug test. At WOT the bike revvs really high so i did it short because it new and not really broken in yet. Only has like 85 miles. Well the plug came out a grayish color. I haven't gotten the threads off yet. But if that second pic you gave me is what it should look like it may be a bit rich. But it didn't really look to bad. So my next step would be testing jet needle position?
