WR400/426/450 Jetting Database

[gloft]

Model (400 - 426 - 450): 03' WR 450F

Timing (WR-YZ): YZ

Main jet: #168

Pilot Jet: # 48

Fuel screw (turns out): 1 1/2

Leak Jet: # 40

Needle model/Clip position: JD Red / pos 3

Airbox lid (on or off): off snorkel removed

Pipe: Stock with Baja baffle insert

Altitude where you ride: 0-3000ft

Temperature where you ride: 65-90deg

Degree of satisfaction: 9/10

[Psychoone]

Model (400 - 426 - 450): 2003 WR450

Timing (WR-YZ): YZ, with YZ Cam

Main jet: 170

Pilot Jet: Stock, 48

Leak: 40

Starter: 70

Fuel screw (turns out): 2 out

Needle model/Clip position: JD blue on the 4th groove

Airbox lid (on or off): snorkel removed

Pipe: Jardine

Air filter: K&N

Altitude where you ride: 0 - 1000 ASL

Boyeson Quickshot ?

Thanks,

Kevin

[momudder]

Model (400 - 426 - 450): 03' WR450

Timing (WR-YZ): WR

Main jet: 168

Pilot Jet: 48

Leak: 40

Fuel screw (turns out): 3

Needle model: stock/3rd

Airbox lid (on or off):On/ Snorkel removed

Pipe: Stock with Vortek tip

Altitude where you ride: 0-5000

Temperature where you ride: 60-90F

AIS: In tact

All free mods done

Degree of satisfaction: 8/10

I just bought this bike and the free mods had been done. When the throttle was wacked open such as you do to clear a log the motor would DIE! I used this data base to come up with my jetting and the leak jet was reccomended by the parts counter guy. Big difference throughout the power range and no more bog when the throttle is wacked. I rated it an 8 since i am unfamiliar with what to expect and left room to improve. thanks for the help all! ?

[JeffWR]

Model (400 - 426 - 450): 05' WR450

All free mods done

Timing: WR

Main Jet: 170 was 165

Pilot: 48 was 45

PAJ: stock ??

Starter Jet: 65 stock

Leak: 40 was 50

ACV: Boyesen Quickshot

TPS: Connected

Fuel screw: Zyp-Ty 1.75 turns out

Needle: JD Red #5

Air box: Snorkle removed

Pipe: stock w/o baffle sometimes use the PMB insert

Altitude: 500-1500

Temp: 60's - 70's

Humidity: 50 - 60%

Satisfaction: 9.8 out of 10 The bike rips with no bog anywhere. I prefer the baffle being out to the PMB insert.

[Blaster21996]

05 WR450

JD Red Clip4

#40 Leak Jet

#48 Pilot Jet

165 Main Jet

Boysen Quick Shot AP Cover

Grey Wire

Throtle Stop Cut

Fliudyne High Capacity Radiators

Snorkle Cut

Red Line Synth Oil

Engine Ice Coolant

Has a stud-d-er at 1/4 throttle cruising. Will try a #160 MJ

Florida (Central) 0-100ft

Temps are around 90, high humidity

[radish150]

99 WR-400, sea-level, high 80´s to low 90´s, super high humidity, JD red needle at number 3 clip, 160 main, MSR needle 2.5 turns out, other jetting stock, drilled out PMB muffler insert. This is the ONLY combination I could get to work here on this bike. Everything is feeling pretty good now, need to decide if the bike runs better with TPS dc´d or not.

Mark Sheldon

[bcavmechanic]

Model: '02 WR426 Canadian model

Timing:Hotcams IN/EX

Main jet: 170

Pilot Jet: 45

Needle: JD Blue 3rd Clip

AP: BK mod and 1 sec shot with Boyesen Quickshot Cover

Fuel screw (turns out): 2

Airbox lid: off

Power now on Carb Inlet

Pipe: FMF Q and Power Bomb header

Altitude where you ride: 100ft to 2500 ft ASL

Temperature where you ride: 10 deg C to 30 deg C

Degree of satisfaction: Runs great everywhere,This Motor Rips!

[dman450f]

05 wr450f

mods done

blue needle #3

#168 main jet

AIS removal kit"highly recommended"

elevation is 3500 to 6500

started right up! seems to run great,no backfire

very happy with this bike!!

[rtrolli69]

Heres my jetting info.Thanks for the starting point INDY it was right in there..my bike is 05 WR 450,timing is WR stock,main jet is #168,pilot is#50,needle postion is JD red in the 5th position,Zip TY fuel adjuster is 1 3/4 turns out,elevation is 4200ft.temp is 90-95 degrees right now.mods are AIS removed,DR D race pipe,snorkel out of air box,gray wire clipped,PWR plus sytem inserts,front&back of carb...The bike is a ROCKET everytime I ride it I fall deeper into the BLUE!!!

[yasotay1]

Model 426

Timing WR

Main jet:155

Pilot Jet:40

Fuel screw (turns out):2 zip ty

Needle model/Clip position:3

Airbox lid off

Pipe:big gun race full system

Altitude where you ride:4000-13000+

Temperature where you ride:70-90+

Degree of satisfaction: okay so far, still need to test at high alt.

Power Now,Boyeson acc. pump cover,Big Gun Full system, BK Mod.

[CuLayTur]

Model 1998 WR 400

Timing YZ

Main jet:165

Pilot Jet:40

Pilot Air Jet: 75

Fuel screw (turns out):2 zip ty

Needle model/Clip position:JD Red in 4th position

Airbox lid off

Pipe:WB E-series w/ 12 disc's

Altitude where you ride:7000-13000+

Temperature where you ride:70-90+

All Free mods

Degree of satisfaction: Never felt this bike run so good. Just plain rips...

Power Now,YZ 450 cam and new Accelerator diaphragm from JDJetting.com with absolutely no bog.

[SmallMonkey]

Model (400 - 426 - 450): 2003 WR450F

Timing (WR-YZ): WR

Main jet: 165

Pilot Jet: 50

Fuel screw (turns out): 2 1/4

Needle model/Clip position: Stock needle 5th of 7

Airbox lid (on or off): on

Pipe: Stock - insert removed

Altitude where you ride: SeaLevel -5000ft

Temperature where you ride: 70-105

Degree of satisfaction: 8.5 of 10 - Still bogs just a tad when on the gas hard from idle.

NEW SETTINGS: - Better, but not there yet.

Model (400 - 426 - 450): 2003 WR450F

Timing (WR-YZ): WR

Main jet: 175

Pilot Jet: 50

Fuel screw (turns out): 2

Needle model/Clip position: Stock needle 5th of 7

Airbox lid (on or off): on

Pipe: Stock - insert removed

Altitude where you ride: SeaLevel -5000ft

Temperature where you ride: 70-105

Degree of satisfaction: 9 of 10 - Still bogs just a tad when on the gas hard from idle

[BergRyder]

Model (400 - 426 - 450): 2001 WR426 Supermoto

Timing (WR-YZ): HotCams

Main jet: 175

Pilot Jet: 48

Fuel screw (turns out): 2 1/4

Needle model/Clip position: OBDR R 4th of 7

Airbox lid (on or off): off, holes cut in airbox, K&N filter

Pipe: Yoshimura RS-3 no insert

Altitude where you ride: SeaLevel -3000ft

Temperature where you ride: 70-100

Degree of satisfaction: 9.5 of 10 - Rips, smooth powerband , no flat spots, starts first kick

[96warrior]

Model (400 - 426 - 450): 2001 WR426

Timing (WR-YZ): WR

Main jet: 170

Pilot Jet: 45

Fuel screw (turns out): stock

Needle model/Clip position: Jd Blue needle, 4'th clipp

Airbox lid (on or off): Off, Uni filter

Pipe: Stock gytr

Altitude where you ride: 1000ft

Temperature where you ride: 60-95

Degree of satisfaction: 9 of 10

[yamageezer]

Here's mine:

Model (400 - 426 - 450): 2005 WR450

Timing (WR-YZ): WR

Grey Wire: Disconnected

TPS: Connected and adjusted per factory spec.

Main jet: 168

Pilot Jet: 45

Pilot air jet: Stock

Leak Jet: 50

Fuel screw (turns out): Zip-Ty - 1.5 out

Needle model/Clip position: JD Red #4

Air box lid (on or off): snorkel removed/ right side open & powernow

Pipe: YZ w/ Pro Moto end

Air filter: No-Toil

Altitude where you ride: 2500' - 4000'

Temperature where you ride: ~50 - 60 degrees. ?

Screams ?

I had problems with poor fuel mileage and 1/4 throttle stumble but when I leaned out the pilot circuit WOW better mileage and no more stumble and she is amazingly fast.

[adrenalinejunky81]

Model (400 - 426 - 450): ;00 WR400

Timing (WR-YZ):Yz

Main jet:168

Pilot Jet:48

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

Needle model/Clip position:3rd

Airbox lid (on or off):off

Pipe:FMF Powercore (straight through)

Altitude where you ride:1000ft?

Temperature where you ride:hot (phoenix)

Degree of satisfaction:8 out of 10

[byggd]

Model (400 - 426 - 450): 02 WR426

Timing (WR-YZ): YZ with 03 exhaust cam

Main jet: 170

Pilot Jet: 40

Fuel screw (turns out): 1 1/2

Needle model/Clip position: JD blue needle postion #3

Airbox lid (on or off): Lid Off

Pipe: White brothers e-series w/six discs and quiet core insert

Altitude where you ride: So Cal 0-4000 ft

Temperature where you ride: 40-100

Degree of satisfaction: Runs awesome quick response/no bog

[tony1970]

Model (400 - 426 - 450): 2005 WR450

Timing (WR-YZ):WR

Main jet:#168

Pilot Jet:#45

Leak Jet:#40

Fuel screw (turns out):1 1/4 , Zip TY

Needle model/Clip position:JD Red #4 position

Boysen Quick Shot

Airbox: Snorkel out, punch outs removed with screen installed.

Filter: Twin Air

Pipe: Stock w/ PMB insert

AIS removed with TT Kit

Altitude where you ride:250-2000ft ASL

Temperature where you ride: Now 50-75 Deg F

Degree of satisfaction: 9 out of 10 Bike rips.

Had problems with the blue needle #3 & 4 position, 1/8 to 1/4 throttle studder. Too rich. Installed Red #4 and cleaned right up. Going to ride a few times and install #40 Leak Jet to compare. ?

12/4/05 Installed #40 leak jet, made a big difference on roll on power.

1/06 Installed Boysen Quick Shot. Helped w/low end snap.

7/1/06 Lowered needle to Red #3 for hotter weather to lean. Runs awesome! #45PJ (stock) has worked better for me all around in starting and low end.

[Matty05]

Model: '05 WR450FT

Timing: WR

Main Jet: 165

Pilot jet: 45

Pilot Air Jet: 80 (stock)

TPS: Connected

ACV: Intact

Grey wire: disconnected

AIS: Sorry, not on Aussie bikes!

Fuel screw: Zip-Ty 1 1/2 turns out

Needle: JD Red #4

Air box: side holes cut out, no snorkel

Pipe: Procircuit Ti4 GP lowboy full system

Fuel: 95 octane premium.

Location: Northern Territory, Australia.

Altitude: Sea level

Temp: 85 - 90*F (~30*c)

Humidity: 80 - 100+%

Satisfaction: 9.8 / 10.

Very crisp and clean running.

[YamahaWR450FMike]

Model (400 - 426 - 450): 2004 WR450FS

Timing (WR-YZ):WR

Main jet: 168

Pilot Jet: 48

TPS: Connected

Fuel screw (turns out): 1 1/2

Needle model/Clip position: 4

Airbox lid (on or off): On

Pipe: Stock with baffle removed

Altitude where you ride: 500 to 1000ft

Temperature where you ride: 70F - 95F

Degree of satisfaction: Love it. Super fast and runs very nice!