Jump to content
kxrob

Kx 250 Jetting Database

Recommended Posts

Well i have decided that we should give this jetting database thing a go

so credit goes to GMOSS357 for the original template from the ktm side of the forums

i will start with mine and update when i improve it

Year:
Model : 2000 KX250
Displacement (cc): 250cc

Carb size (38 or 36mm): PWK38S (stock)
Slide: stock
Main jet: 158
Pilot Jet: 45
Air screw (turns out): 1 1/2 winter 1 3/4 summer
Needle model/Clip position: n3we (stock) 3rd position
Altitude where you ride: 0-500 ft
Temperature: winter ( 20 derees celsius (68 f) /summer 35 degrees celsius (95 f)

Reeds: v force 3
Pipe/silencer: fmf gnarly / fmf power core 2
Head mod: stock
Other mods: nil
Type of fuel: 95 octane (93 us grade i beleive) 40:1 castrol activ semi syn
Where in the powerband do you ride (Lugger - for technical stuff, or wide open - desert / MX): lugger/75% mid range
Degree of satisfaction: 80%
And finally: how much spooge 1) none, 2) little, 3) medium, 4) lots: 1 (none) but oil pipe tip

Notes:


next step is to drop pj to 42 and change needle to a suzuki needle (maybe nedj)
when i make the switch to 50:1 full synthetic
and repack silencer and clean out gnarly pipe

 

this is my pipe after last ride

image.jpeg

Edited by kxrob

Share this post


Link to post
Share on other sites

 

Posted Today, 03:08 PM

 

2001
Kx250
265cc 
38mm keihin 
Stock slide 
150 main jet
42 pilot jet
Air screw 1.5 turns out
Stock needle 2nd clip
Altitude 1300ft 
V force 3 reeds
Fmf fatty/pc 304 shorty
Stock head
93 octane 40:1
Woods/free ride 
2, little spooge 
 
 
Edited by kxrob

Share this post


Link to post
Share on other sites

2000kx250

Pilot 52

Main 158

Air screw 1/12

Neddle stock N3WE clip 3rd position

Engine stock

Castrol R30 32/1

Best smelling bike at the track !!

Sea level - 500ft

Spooge.....yip

Fun to ride..... 🙂

Share this post


Link to post
Share on other sites

Not at this stage. The bike has more than enough power and does not foul plugs. I'm not going to lean out the bike to chase a very small amount of power and will cash in on the rich running longdivity.

Share this post


Link to post
Share on other sites

As I said in my last post....the bike has more than enough power. For me that is. So I'll get my "rideability" by getting the fork's and rear shock rebuilt.as they are all std.

Share this post


Link to post
Share on other sites

UPDATE

Year: 2000

Model : KX250

Displacement (cc): 250cc

Carb size (38 or 36mm): PWK38S (stock)

Slide: stock (8)

Main jet: 158

Pilot Jet: 42

Air screw (turns out): 1 1/2 winter 1 3/4 summer

Needle model/Clip position: NECW Suzuki needle 3rd clip

Altitude where you ride: 0-500 ft

Temperature: winter ( 20 derees celsius (68 f) /summer 35 degrees celsius (95 f)

Reeds: v force 3

Pipe/silencer: fmf gnarly / fmf power core 2

Head mod: stock

Other mods: nil

Type of fuel: 95 octane (93 us grade i beleive) 40:1 castrol power 1 tts full synthetic

Where in the powerband do you ride (Lugger - for technical stuff, or wide open - desert / MX): lugger/75% mid range

Degree of satisfaction: 95%

And finally: how much spooge 1) none, 2) little, 3) medium, 4) lots: 1 (none) pipe clean as

Notes:

pj now 42

Needle : necw

repacked silencer and cleaned out gnarly pipe

this is my pipe after last ride

image.jpeg

Edited by kxrob

Share this post


Link to post
Share on other sites

calling all kx250 jetting experts  😉

 

thinking of raising clip on NECW needle to 2nd clip from 3rd clip

how does this compared to say a NECJ in 3rd clip position

Share this post


Link to post
Share on other sites

calling all kx250 jetting experts  😉

 

thinking of raising clip on NECW needle to 2nd clip from 3rd clip

how does this compared to say a NECJ in 3rd clip position

 

The NECJ needle is 1 full step leaner on the starting diameter than the NECW, which effects up to just under 1/4 throttle. beyond about 1/4 throttle both needles are the same.

Share this post


Link to post
Share on other sites

The NECJ needle is 1 full step leaner on the starting diameter than the NECW, which effects up to just under 1/4 throttle. beyond about 1/4 throttle both needles are the same.

so i full clip ?

 

mine just seems a little bit flat of idle , so thinking it was a bit rich still

Share this post


Link to post
Share on other sites

so i full clip ?

 

mine just seems a little bit flat of idle , so thinking it was a bit rich still

 

No, The clip heights between the 2 needles( NECW & NECJ) is the exact same. The starting diameter of the NECJ is slightly thicker, which makes it leaner. The next leaner needle in the Suzuki NExx series after the NECW would be an NEDJ, which is 1/2 clip position richer than the NECJ.

Share this post


Link to post
Share on other sites

No, The clip heights between the 2 needles( NECW & NECJ) is the exact same. The starting diameter of the NECJ is slightly thicker, which makes it leaner. The next leaner needle in the Suzuki NExx series after the NECW would be an NEDJ, which is 1/2 clip position richer than the NECJ.

 

so if i want to lean it out with out buying a new needle and drop it down 1 clip (from 3rd to 2nd)

how would it compare to the NECJ  (leaner or richer running ) in the 1/4 throttle to 1/2 throttle range

Share this post


Link to post
Share on other sites

so if i want to lean it out with out buying a new needle and drop it down 1 clip (from 3rd to 2nd)

how would it compare to the NECJ  (leaner or richer running ) in the 1/4 throttle to 1/2 throttle range

 

With the NECJ in #3 and the NECW in #2 clip position, and between 1/4 and 1/2  throttle, the NECW should  be slightly leaner.

Share this post


Link to post
Share on other sites

Ok

What is your take on it feeling a bit flat just off idle

Do you think it's rich ?

Share this post


Link to post
Share on other sites

Ok

What is your take on it feeling a bit flat just off idle

Do you think it's rich ?

 

It's tough to tell without being there or listening to the bike. You're going to have to do some testing. Start by  lowering the needle, go from 3# clip position to #2 and see what difference that makes.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...