Jetting D-Base for CRF250R

A thread like this exists over in the YZ/WR 250F forum, and I thought it would be nice to have one here. Here is the template:

Model Year:

Main jet:

Pilot Jet:

Leak Jet:

Fuel screw (turns out):

Needle model/Clip position:

Airbox mods:

Pipe:

Altitude where you ride:

Temperature where you ride:

Other mods:

Degree of satisfaction:

Try not to fill the thread with other topics. Jetting questions should probably be directed to the Jetting forum. This will help make jetting searches more productive. So go ahead and post your specs!!

Mod: Sticky?

Model Year: 2008

Main jet: 178

Pilot Jet: 48

Leak Jet: Stock

Fuel screw (turns out): 2 Turns

Needle model/Clip position: stock needle, 3rd position

Airbox mods: None

Pipe: Stock

Altitude where you ride: 6000'

Temperature where you ride: 50-60F

Other mods: None

Degree of satisfaction: Bike starts far more easy than stock. But there is some bog with the first 1/4 throttle turn. Pulls very hard and strong above 1/4 turn on the throttle.

09,jd jet kit 190 main red needle 5th clip,42 pilot,55 leak,1 3/4 turns out, 8thou ex,4thou in,no other mods,20-30 deg C, 0-2000 feet, Runs & pulls clean, no starting probs A++ NO bog whatsoeva!

What to do with my 08 crf250r i just instaled a merge racing leak jet and a jd jetting kit i have way to much bog on the bottom end, im using the red needle the clip is on the 4th position and a 190 main and im riding at sea level in vancouver canada, all the other jets are stock

Model Year:2007

Main jet:172

Pilot Jet:42

Leak Jet:45

Fuel screw (turns out):2 1/4

Needle model/Clip position:3rd

Airbox mods:none

Pipe:stock

Altitude where you ride:0-1000

Temperature where you ride:50-70

Other mods:removed baffle plate in float bowl, turned ap timing screw 2 1/2 turns in

Degree of satisfaction:Very high :thumbsup: no bog at all!

What to do with my 08 crf250r i just instaled a merge racing leak jet and a jd jetting kit i have way to much bog on the bottom end, im using the red needle the clip is on the 4th position and a 190 main and im riding at sea level in vancouver canada, all the other jets are stock

did you not read what the first post said?

sorry im new at this yes i did read the first add thanks!

Model Year: 2008

Main jet: 168 winter, 162 summer

Pilot Jet: 40

Leak Jet: 40

Fuel screw (turns out): 1.5 to 2.25 Turns

Needle model/Clip position: stock needle, 3rd position

Airbox mods: None

Pipe: Stock

Altitude where you ride: 4,000+ ft.

Temperature where you ride: 35-105F

Other mods: None

Degree of satisfaction: Starts good hot or cold and pulls hard, but I'm still looking for the right needle...

Model Year:2007

Main jet:175

Pilot Jet:42

Leak Jet:65

Fuel screw (turns out):2 1/4

Needle model/Clip position:3rd

Airbox mods:none

Pipe:stock

Altitude where you ride:0-2000

Temperature where you ride:50-80

Other mods:Boyeseen QS2

Degree of satisfaction:no bog at all

Model Year: 2006 CRF250R

Main jet:[ 172 stock] 170

Pilot Jet:[40 stock] 45

Leak Jet:[55 stock] 50

Fuel screw (turns out):[1-3/4 stock] 1-1/2

Needle model/Clip position:[NHFS 3rd clip] stock

Carb mods: float bowl baffle remove,Merge racing AP spring

Airbox mods:stock w/ twin air filter

Fuel: pump gas

Pipe:White brothers dual aluminum

Altitude where you ride:0-1000

Temperature where you ride: 50-80 F

Other mods: Hotcam stage 2

No bog whatsoever very crisp sharp throttle response pulls clean from bottom to top.Starts 1st or 2nd kick most of the time.

Edited by dirtracker
What to do with my 08 crf250r i just instaled a merge racing leak jet and a jd jetting kit i have way to much bog on the bottom end, im using the red needle the clip is on the 4th position and a 190 main and im riding at sea level in vancouver canada, all the other jets are stock

What size pilot is in it to start with? I can't remember which adjustable leak jet says to remove the leak jet completely. It might be the merge. I don't know much about the JD jetting kit, but the 190 is really rich. I can get them to run real strong without the JD jetting kit and just playing with the stock set up with the addition of the adjustable leak jet. How far in do you have the screw turned in on the adj leak jet? I know on my kids 08, it's almost all the way in. His has the R&D adjustable leak jet with a 42 pilot and a 172 main. Needle in the 3rd position and who knows how far the mixture screw is out. It runs hard!

Also, is there any other work done to it like head porting?

Here's a site that has stock crf250's and crf250x's it shows stock jetting and has several jetting charts.

http://rickramsey.net/CRF250X.htm

Model Year: 2008

Main jet: 172

Pilot Jet: 45

Leak Jet: 40

Fuel screw (turns out): 1 Turn winter 1/2 turn summer

Needle model/Clip position: stock needle, 3rd position

Airbox mods: None

Pipe: FMF Q

Altitude where you ride: 600'

Temperature where you ride: 30-100+F

Other mods: Rekluse EXP 2.0

Degree of satisfaction: easy starts cold or hot, runs great

Model Year:2007

Main jet:172

Pilot Jet:42

Leak Jet:45

Fuel screw (turns out):2 1/4

Needle model/Clip position:3rd

Airbox mods:none

Pipe:stock

Altitude where you ride:0-1000

Temperature where you ride:50-70

Other mods:removed baffle plate in float bowl, turned ap timing screw 2 1/2 turns in

Degree of satisfaction:Very high :bonk: no bog at all!

Same, same. No bog/exact setting

Model Year: 2009

Main jet: 172 winter, 168 summer

Pilot Jet: 42 winter, 38 summer

Leak Jet: 70

Fuel screw (turns out): 2.25

Needle model/Clip position: NLCT / 3rd from top

Airbox mods: None backfire screen not removed

Pipe: FMF 4.1 with megabomb

Altitude where you ride: 1000' approx

Temperature where you ride: 35-105 degrees

Other mods: ported head, 37mm carb bored to 38.5

Degree of satisfaction: starts and runs great no bogs

Bump

2006 CRF250r

176 main

45 pilot

NKBT needle on 3rd clip from bottom (of 5)

100-2500', 60-90 deg F

Mostly stock.  Bike runs fine.

 

TomJV

Edited by tomjv

Model Year: 2005
Main jeticon1.png: 172
Pilot Jet: 45
Leak Jet: stock
Fuel screw (turns out): 2

Needle model/Clip position: stock/3rd
Airbox mods: No Toil filter cage
Pipe: stock
Altitude where you ride: 800-3500
Temperature where you ride: 60-85
Other mods: 2008 higher comp piston
Degreeicon1.png of satisfaction: Very Good

2007 CRF250R

Main: 178

Pilot: 42

Leak: 50

Fuel: 2 1/4

AP timed to squirt just as throttle plate clears the stream.

Stock compression, stock exhaust (fresh repack), stock intake, Twin Air filter. Stock valves, set correctly.

Elevation 750 meters, Temperature avg 10-20 degrees C. Alberta, Canada

Varying terrain. Bush roads, single track, prairie, mountains, sand, dirt, hard pack.

This bike had a severe lean bog issue. Would flame out if you twisted the throttle any amount from low RPM or idle if it wasn't done relatively slowly. Cleaned carb, checked seals and AP diaphragm, all ok. Had to dig deeper.

Since tuning the AP timing and leak jet the bog is completely gone. Squirt duration of the AP on the bench was .10 seconds with stock #70 leak jet and started too late. Duration is now .25 seconds with #50 leak jet and starts as soon as throttle plate clears the stream.

Smooth acceleration, pulls strong through RPM range. Slight popping on deceleration from high RPM's. Rides well in all terrain.

Header pipe does not glow when sitting and idling.

Edited by techgreg

Model Year:2007

Main jet:172

Pilot Jet:42

Leak Jet:45

Fuel screw (turns out):2 1/4

Needle model/Clip position:3rd

Airbox mods:none

Pipe:stock

Altitude where you ride:0-1000

Temperature where you ride:50-70

Other mods:removed baffle plate in float bowl, turned ap timing screw 2 1/2 turns in

Degree of satisfaction:Very high http://www.thumpertalk.com/public/style_emoticons/#EMO_DIR#/thumbsup.gif no bog at all!

I did this same setup on my 2007 crf250r and I experienced no bog at all, absolutely stoked about this, thanks seth240

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