WR400/426/450 Jetting Database

Year: 2009

Model (400 - 426 - 450): 450

Cam Timing (WR/YZ): WR

Main jet: 165

Pilot Jet: 48

PAJ: Stock

Leak Jet: 48

Starter Jet: Stock

Fuel screw (turns out): 1 1/2

Needle Model/Clip position: JD Red needle 5th clip

Grey Wire Mod (Y/N): Y

TPS Connected (Y/N): Y

Airbox Snorkel/Lid (on or off): off

AIS Removed (Y/N): Y

Airfilter Brand: Stock

Exhaust Brand: Stock (PMB Insert)

Average Altitude: 650-900

Average Temperature: 65-85F

Average Humidity: Florida-like :)

Year:2007

Model (400 - 426 - 450):450

Cam Timing (WR/YZ):WR

Main jet:#168*

Pilot Jet:#48*

PAJ:GYTR-AIS

Leak Jet: pluged & relocate*

Starter Jet:GYTR-AIS

Fuel screw (turns out):MERGE 1.5 OUT

Needle Model/Clip position:GYTR-AIS P-4

Grey Wire Mod (Y/N):Y

TPS Connected (Y/N):Y

Airbox Snorkel/Lid (on or off):OFF

AIS Removed (Y/N):Y (GYTR KIT)

Airfilter Brand:Twin foam

Exhaust Brand:stock, less baffel, w/p-shooter

Average Altitude:2-4

Average Temperature:high ?

Average Humidity: high?

Degree of Satisfaction (0-10):9

Additional Mods/Comments:

Used all GYTR AIS parts execpt,main,pilot,& leak as noted(*).Also installed

Merge: FMS,APS & ALJ(*) 1 turn out

What an amazing differance,And all I wanted wes to debog.

Edited by el bud
spell check & add ALJ setting

Year:2007

Model (400 - 426 - 450):450

Cam Timing (WR/YZ):WR

Main jet:168 (162 stock)

Pilot Jet: 48 (45 stock)

PAJ:Stock

Leak Jet: 50 (60 stock)

Starter Jet: Stock

Fuel screw (turns out):MSR 3 out

Needle Model/Clip position: Yamaha NFLR/4th

Grey Wire Mod (Y/N):Y

TPS Connected (Y/N):Y

Airbox Snorkel/Lid (on or off): off

AIS Removed (Y/N):Y

Airfilter Brand: Stock

Exhaust Brand:Lexx MXE slip-on

Average Altitude: 300 to 1500

Average Temperature:55-100 degrees F

Average Humidity: 85%

Degree of Satisfaction (0-10): 10

Additional comments::smashpc::banana::thumbsup:

Year:2000

Model (400 - 426 - 450):WR400

Cam Timing (WR/YZ):WR

Main jet:168

Pilot Jet:45

PAJ:75

Leak Jet:200

Starter Jet:65

Fuel screw (turns out):3-1/4 OUT

Needle Model/Clip position:4

Grey Wire Mod (Y/N):Y

TPS Connected (Y/N):Y

Airbox Snorkel/Lid (on or off):OFF

AIS Removed (Y/N):N

Airfilter Brand:UNI

Exhaust Brand:STOCK

Average Altitude:900 above sea level

Average Temperature:75

Average Humidity:75

Degree of Satisfaction (0-10):8

Additional Mods/Comments:Still dialing in seems to be a bit lean at times still,but overall runs great,and for anyone wondering I live in Georgia maybe it's the humidity...

Year:2007

Model (400 - 426 - 450):450

Cam Timing (WR/YZ):WR

Main jet:170 (162 stock)

Pilot Jet: 48 (45 stock)

PAJ:Stock

Leak Jet: stock

Starter Jet: Stock

Fuel screw (turns out):tusk 2 -1/8 turns out

Needle Model/Clip position: stock non- adjustable

Grey Wire Mod (Y/N):Y

TPS Connected (Y/N):Y

Airbox Snorkel/Lid (on or off): off

AIS Removed (Y/N):Y

Airfilter Brand: Twin air

Exhaust Brand:08 YZ450 system

Average Altitude: 300 to 1500

Average Temperature:28-38 degrees C

Average Humidity: 85%

Degree of Satisfaction (0-10): 10

I first start with the 168 main but the bike is lean a bit. Put the 170 main and everything change . Rev like an YZ.

Year: 2009

Model 2009 WR

Cam Timing (WR/YZ):WR

Main jet:162

Pilot Jet:48

PAJ:110

Leak Jet:45

Starter Jet:65

Fuel screw (turns out):2

Needle Model/Clip position: YZ 450 needle - NFLR middle clip

Grey Wire Mod (Y/N):No

TPS Connected (Y/N): yes

Airbox Snorkel/Lid (on or off):On

AIS Removed (Y/N):Y

Airfilter Brand: Twinair

Exhaust Brand: Drd full system

Average Altitude:4000 to 7000 density altitude

Average Temperature:15 to 30 deg celcius

Average Humidity:40

Degree of Satisfaction (0-10):9

Additional Mods/Comments Backfire screen removed from air filter cage

Merge racing spring

Merge racing brass fuel screw

Year: 2006

Model: WR450F

Cam Timing: WR

Main jet: 175

Pilot Jet: 55

PAJ: stock

Leak Jet: stock

Starter Jet: stock

Fuel screw (turns out): 2 (Works Connection adj. fuel screw)

Needle Model/Clip position: GYT-R 7 grooves, clip in middle position (needle came with Yamaha AIS removal/de-restricting kit)

Grey Wire Mod (Y/N):Y

TPS Connected (Y/N):Y

Airbox Snorkel/Lid (on or off): Off and air box opened up per GYT-R instructions.

AIS Removed (Y/N): Y

Airfilter Brand: stock

Exhaust Brand: FMF PowerBomb header and FMF Powercore muffler with spark arrester.

Average Altitude: 700 ft.

Average Temperature: 10-100F yearly, currently averaging 20F

Average Humidity: 30-90% yearly, currently 64%

Degree of Satisfaction (0-10): 9

Additional Mods/Comments: Jetting has been somewhat problematic after installing the FMF exhaust system. Previously I had the stock exhaust system with a ProMoto Billet insert, 168 main, 48 pilot, needle in the middle position and the jetting was spot on. After the FMF system I had excessive decel popping and back firing. I searched this database and couldn't find what I thought was a good starting point. After talking to the guys at the local Yamaha shop this is what I went with. Decel popping/back firing gone. Spark arrester screen a light brown color.

When the weather warms up I'm sure I'll have to change the needle setting and fuel screw though to fine tune it.

Year: 2011

Model: WR450

Grey Wire Mod: Yes

Main Jet: 170

Pilot jet: 48

Leak: 45

Starter: 65

Needle Jet: Red 4th position

Fuel Screw: 1 1/2 out

AIS removal:Yes

Airbox Mod :Yes

Stock Exhaust: Pea shooter removed 

Altitude: 0-2000ft

Avg temp: I live on the North Oregon Coast it's wet !!  50-70 Degrees

Degree of Satisfaction ( 0-10 ) 9 

Starts up cold with Push Button + Choke, Idles fine without choke after 10 sec

Year:2008
Model (400 - 426 - 450):  WR450F
Cam Timing (WR/YZ):  HOT CAMS YZ
Main jet:  170
Pilot Jet:  45
PAJ:  75
Leak Jet:  50
Starter Jet:  75
Fuel screw (turns out):  1.6875
Needle Model/Clip position: NFPQ 3RD
Grey Wire Mod (Y/N):Y
TPS Connected (Y/N):  YES AND CALIBRATED
Airbox Snorkel/Lid (on or off):  FULLY OPENED
AIS Removed (Y/N):  YES
Airfilter Brand:  UNI
Exhaust Brand:DUBACH RACING SS FULL SYSTEM
Average Altitude: 2000 FT
Average Temperature: 20
Average Humidity: 75
Degree of Satisfaction (0-10): ELEBUN
Additional Mods:

 

CARB:  APUMP UPGRADE (NEWER CHECK VALVE SYSTEM) USING 2008 CRF COMPONENTS

             ZIPTY RACING HOT START NUT (ALUMINUM)

 

 MOTOR:  FULL STAGE 3 PORT AND POLISH (AS RACING)

                  BARNETT CLUTCH PACK

                 .060" CLUTCH SPRING BOLT SPACERS

 

IGNITION: DYNATEK FS IGNITION MODULE

                 STOCK MAP # 3

                  MODIFIED MAP # 2: AGGRESSIVE ADVANCE CURVE, WITH ALL 1+ ADVANCE

Edited by TheKoolAidMadeMeSick

Year: 1999
Model (400 - 426 - 450): 400
Cam Timing (WR/YZ): wr
Main jeticon1.png: stock
Pilot Jet: stock
PAJ: stock
Leak Jet:stock
Starter Jet: stock
Fuel screw (turns out): 1 1/2
Needle Model/Clip position: 3 clip stock needle
Grey Wire Mod (Y/N): yes
TPS Connected (Y/N): yes
Airbox Snorkel/Lid (on or off): one
AIS Removed (Y/N): no
Airfilter Brand: uni
Exhausticon1.png Brand: stock with spark arrestor
Average Altitude: 89FT        Garden Grove California
Average Temperature: 65.6F
Average Humidity: 62%
Degree of Satisfaction (0-10): 8 being that i am happy. the other 2 being that i think there is something that needs fixing but not sure yet. still playing with the air/fuel - pilot screw.  
Additional Mods/Comments: no mods other than i am running a 14t front sprocket and 48t rear sprocket, 120 rear desert tire with 15psi front and rear.

 

i had graduated 2013 mmi phoenix arizona in YamaPro. they only teach you so much just to get you on your feet. i just got my street legal wr400fl this year. it was not running and needed some work. got her for $1,500. now she is set up for the desert and running pretty smooth. i am about ready to put her up for sale in a bit. she will be going for an average price for a running street legal and current tag WR400fl 

Year: 99
Model (400 - 426 - 450): 400
Cam Timing (WR/YZ): yz
Main jet: 175
Pilot Jet: 48
Fuel screw (turns out): 1 3/4
Needle Model/Clip position: jd blue 5th
TPS Connected (Y/N): N
Airbox Snorkel/Lid (on or off): off
AIS Removed (Y/N): Y
Airfilter Brand: K&N
Exhausticon1.png Brand:  staintune
Average Altitude: 0 - 100m
Average Temperature: 24 c
Degree of Satisfaction (0-10): 10
Additional Mods/Comments: vortex cdi, wiseco high comp piston, loud as f@#k exhaust, will rip your arms off

WR450F 2003

WR Timing

168M

48P

40LEAK

Stock air jet

Stock Power jet

Stock needle set @ clip pos 5

TPS Connected

Altitude 0 - 100 m

Average temp 15C - 30C

Air box removed

GYTR Baffle

SCAR adjustable fuel screw

Satisfied 9/10 

Year:                                         2008
Model (400 - 426 - 450):           WR450F
Cam Timing (WR/YZ):              WR
Main jet:                                    Stock
Pilot Jet:                                    Stock
PAJ:                                          Stock
Leak Jet:                                Stock
Starter Jet:                                Stock
Fuel screw (turns out):              ?
Needle Model/Clip position:      ?
Grey Wire Mod (Y/N):               Yes
TPS Connected (Y/N):              No
Airbox Snorkel/Lid (on or off):   Off
AIS Removed (Y/N):                 Yes
Airfilter Brand:                           Stock
Exhaust Brand:                     YZ header, cleaned out original muffler
Average Altitude:                      300 ft
Average Temperature:             6 celsius, top 32 celsuis, bottom 35 celsius below
Average Humidity:                   80-95 %
Degree of Satisfaction (0-10):  4

 

 

Additional Mods/Comments:

 

I have the bog problem and i need some guidence for fixing this.

 

English is not my native language but i googled most stuff here, but if someone would please help me with photos with what i need to buy and to do, or just general directions, i would be a most grateful.

 

The problem started when i opened up the exhaust for YZ standards.

 

I read the how to eliminate bog thread, but i do not understand it all. And remember that i have never opened a carburator

 

Best regards

Edited by Agazza

Year:  2008
Model (400 - 426 - 450):  450
Cam Timing (WR/YZ):  WR
Main jet:  Unknown
Pilot Jet:  Unknown
PAJ:  Unknown
Leak Jet:  Unknown
Starter Jet:  Unknown
Fuel screw (turns out):  N/A
Needle Model/Clip position:  GDDUR, No. 3 groove 
Grey Wire Mod (Y/N):  Y
TPS Connected (Y/N):  Y
Airbox Snorkel/Lid (on or off):  Lid on, snorkel removed
AIS Removed (Y/N):  Y
Airfilter Brand:  Stock
Exhaust Brand:  Stock with silencer/spark arrestor removed
Average Altitude:  6,000'-9,000'
Average Temperature:  55F-85F
Average Humidity:  10%
Degree of Satisfaction (0-10):  9
Additional Mods/Comments:  Just got the bike and am very pleased.  Pilot jet and Main jet seem very close to correct, had to incrementally raise the Needle clip 2 notches to eliminate 1/4-3/4 throttle overly rich condition.  FMF exhaust in the near future with edits to follow.  

Year:
Model (400 - 426 - 450): WR450F
Cam Timing (WR/YZ): 06 YZ exhaust cam
Main jet: 168
Pilot Jet: 48
PAJ: stock (70)
Leak Jet: Between 40 and 50.  40 is a bit too rich, 50 lacks a bit of crispness.
Starter Jet: stock (72)
Fuel screw (turns out): 2.5-3
Needle Model/Clip position: JD Red-4
Grey Wire Mod (Y/N): Y
TPS Connected (Y/N): Y
Airbox Snorkel/Lid (on or off): snorkel removed
AIS Removed (Y/N): Y
Airfilter Brand: Twin Air/Uni/No-toil
Exhaust Brand: FMF Q4.  Stock header
Average Altitude: 2000
Average Temperature: 70
Average Humidity:
Degree of Satisfaction (0-10): 9.5
Additional Mods/Comments: Followed Krannie's recommendations for the 2008 CRF450F accelerator pump kit (Honda Part# 16021-MEN-A01), and the tokyo mods accelerator pump spring.  Highly recommend that combo - the bike rips and has better throttle response than stock YZ's and fuel injected bikes IMHO.

 

I have been experimenting with different leak jets.  50 eliminated the bog, but wasn't perfect.  40 is a little too rich.  Next attempt will be a 45.  

For some reason, my bike likes a richer pilot circuit than others.  It starts first kick hot or cold. E-start works 90% of the time, even though YZ cams are known for having too much decompression for e-start to work.

 

Over 6,000 feet = JD Red-3, 165 MJ

Over 9,000 feet = JD Red-3, 160 MJ

Year: 2002
Model (400 - 426 - 450): YZ 426
Cam Timing (WR/YZ): yz
Main jet: 168
Pilot Jet: 48

Starter Jet: Stock 72
Fuel screw (turns out): 3/4
Needle Model/Clip position: Y356  4th
TPS Connected (Y/N): Y
Airbox Snorkel/Lid (on or off): off
AIS Removed (Y/N): ?
Airfilter Brand: UNI

No grey wire mod.
Exhausticon1.png Brand:  FMF Silencer

Average Altitude: 0 - 100m
Average Temperature: WInter 65 Summer 110

Humidity: Dry
Degree of Satisfaction (0-10): 9/10
Additional Mods/Comments: Gearing 14/47, IMS 3 Gal.

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