WR400/426/450 Jetting Database

Model (400 - 426 - 450): 2005 WR450

Timing (WR-YZ): WR

Main jet: 160 (tried 170 & 168 but they were sluggish)

Pilot Jet: Stock 45

Fuel screw (turns out): ZipTy - 1.5 to 2 out

Needle model/Clip position: JD Red #4

Airbox lid (on or off): on...snorkel removed

Pipe: Stock, OEM restrictor removed

air filter: Stock

Altitude where you ride:0-300' ASL (Mobile, AL)

Temperature where you ride: 80-100 degrees now.

Degree of satisfaction ... :D:prof::prof: waaaaaaaaayyyyy stronger. :applause:

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

Timing (WR-YZ):WR

Main jet:168

Pilot Jet:48

Leak Jet :40

Needle model/Clip position:JD RED #5

Airbox lid (on or off):On-snorkle out

Pipe:FMF Titanium PowerCore W/Quiet insert

Altitude where you ride:1000-3000ft

Temperature where you ride:35 deg. to 100 deg farenheight

Degree of satisfaction: :ride::ride: I installed the kit and

am running a little richer red #5 rather than chance being too lean and the

bike runs EXCELLENT even in cold weather all the way to Swealtering Heat!! :ride:

Model (400 - 426 - 450): 06 WR450

Timing (WR-YZ):YZ

Main jet:168

Pilot Jet:stock

Fuel screw (turns out):1.5

Needle model/Clip position:#3

Airbox lid (on or off):On, side cut out

Pipe:free mod

Altitude where you ride:1000'

Temperature where you ride:80F

Degree of satisfaction:very good

I did the free mods, installed the Gytr ais kit, and it ran pretty good. I had a little burble in the upper mid range, moved the clip to pos 3, runs like a champ now.

Model (400 - 426 - 450): 06 WR450

Timing (WR-YZ): YZ

Main Jet: 165

Pilot Jet: Stock (45)

Fuel Screw: 1.25 turns out

Needle: Stock shimmed with 2 washers

Airbox Lid (on or off): off, side cut out

Pipe: Stock header, Q2 muffler

Altitude where you ride: 3500-9000ft

Temperature where you ride: 60-90 F

Degree of Satisfaction: Very Good

I did all free mods excluding clutch mod. I found the JD red needle to be too rich unless in 3rd clip position. Runs better with stock needle shimmed. I measured the JD red compared to stock needle and JD is about .001" smaller in dia. throughout.

Model (2005 WR 450):

Timing (WR):

Main jet: 168

Pilot Jet: 45

Fuel screw (turns out): 1 1/2

Needle model/Clip position: JD Red - Notch #5

Airbox lid (on or off):Off

Pipe: YZ muffler on WR header pipe

Altitude where you ride: 0-1000

Temperature where you ride: 50-85 Winter/Summer

Degree of satisfaction: As of 27 August 07 - :thumbsup:

It's taken a bit to get here - :ride:

Model :2005 WR 450

Timing : YZ Gray wire disconnect

Main jet:168

Pilot Jet:48 supplied w/ ais kit

Fuel screw (turns out): zip-ty 1 1/2

Needle model/Clip position:yamaha supplied w/ais kit 4th pos

Airbox lid (on or off): baffle removed, side holes cut per Yamaha instructions

Pipe:stock w/ restrictor removed

Bike ran good w stock main jet (155) but seemed hot (header glow), popping on decel

added 168 jet and at same time Zip-ty needle, bike now idles and runs great!

Better idle , good throttle response less popping on decel

Year: 2005

Model (400 - 426 - 450): 450

Cam Timing (WR/YZ): WR

Main jet: 165

Pilot Jet: 48

PAJ: Stock

Leak Jet : 50

Starter Jet: 68

Fuel screw (turns out): 1.5 Tusk /Dubach Racing

Needle Model/Clip position: JD Red #5

Grey Wire Mod (Y/N): Y

TPS Connected (Y/N): Y

Airbox Snorkel/Lid (on or off): Snorkelectomy

AIS Removed (Y/N): Y

Airfilter Brand: Uni

Exhaust Brand: FMF PowerCore4 with the Quiet Core

Average Altitude: 1000 ft

Average Temperature: spring/fall (75 -90), summer (90-110), winter (45-60)

Average Humidity: ~10%

Degree of Satisfaction (0-10): 10

Additional Mods/Comments:R&D Lightning P-38, Powernow. The summer time is a killer in Arizona, so my jetting gets a lot leaner when it gets hot.

Everyone should have a JD Kit :thumbsup:

Year: 2005

Model (400 - 426 - 450): 450

Cam Timing (WR/YZ): WR

Main jet: 168

Pilot Jet: 45

PAJ: Stock

Leak Jet : 40

Starter Jet: 68

Fuel screw (turns out): 1.75 Ty

Needle Model/Clip position: JD blue #4

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: White Bros E2

Average Altitude: 1000- 4000 ft

Average Temperature: 75

Degree of Satisfaction (0-10): 5

Additional Mods/Comments: Boysen Quick Shot

I fowled a plug running a this setting. This was tood rich. Going to try a 165 main or possible a needle change. I don't see how people can run a 170 main?? I will update when I have it right. Adding the Boysen Quickshot was a big improvement and then lowering the leak jet to a 40 made the low initial grunt better.

Year: 2006

Model (400 - 426 - 450): WR450F

Cam Timing (WR/YZ): WR

Main jet: 170

Pilot Jet: 48 (GYT-R AIS removal kit)

PAJ: stock

Leak Jet : stock

Starter Jet: stock

Fuel screw (turns out): 2.25

Needle Model/Clip position: 3rd from top '04 needle (GYT-R AIS removal kit)

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: PMB insert in stock

Average Altitude: 0-1000

Average Temperature: 70

Average Humidity: 80

Degree of Satisfaction (0-10): 10

Additional Mods/Comments: cool stickers, mud, and sticks.

Year: 2006

Model (400 - 426 - 450): WR450F

Cam Timing (WR/YZ): WR

Main jet: 168

Pilot Jet: 45

PAJ: stock

Leak Jet : stock

Starter Jet: stock

Fuel screw (turns out): 2.0

Needle Model/Clip position: JD Blue 3rd position

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: UNI

Exhaust Brand: PMB insert in stock

Average Altitude: 0-1500

Average Temperature: 75

Average Humidity: ?

Degree of Satisfaction (0-10): 8

Additional Mods/Comments: Works fine

Year:2004

Model (400 - 426 - 450):450

Cam Timing (WR/YZ):WR

Main jet:170

Pilot Jet:STOCK

PAJ:?

Leak Jet :?

Starter Jet:?

Fuel screw (turns out):2

Needle Model/Clip position:BLUE/3RD CLIP

Grey Wire Mod (Y/N):N

TPS Connected (Y/N):?

Airbox Snorkel/Lid (on or off):ON

AIS Removed (Y/N):NO

Airfilter Brand:STOCK

Exhaust Brand:FMF Q2

Average Altitude:3000

Average Temperature:80

Average Humidity:?

Degree of Satisfaction (0-10):10

Additional Mods/Comments:

STARTS, IDLES, ACCELS, DECELS, GREAT

INCREASE REAR SPROCKET ONE TOOTH

DECREASED FRONT SPROCK ONE TOOTH

NORCAL TRAIL RIDER

05' WR450 Jetting Guide for about 500ft above sea level

Winter Jetting

Average ambient temperatures: 40°F to 80°F

Main jet: 168

Pilot Jet: 48

Fuel screw (turns out): ZipTy - 1.5 turns

Needle model/Clip position: JD Red 5th clip

Air box: Snorkel out, "punch-outs" removed

Pipe: stock, plug removed

Summer Jetting:

Average ambient temperatures: 60°F to 100°F

Main jet: 168

Pilot Jet: 45

Fuel screw (turns out): ZipTy - 1.75 turns

Needle model/Clip position: JD Red 4th clip

Air box: Snorkel out, "punch-outs" removed

Pipe: stock, plug removed

These settings were taken from a compilation of several members' inputs. Here is the link to the list of those members' settings. 2005_wr450f_jetting_dbase

Year: 2006

Model (400 - 426 - 450): 450

Cam Timing (WR/YZ): YZ

Main jet: 165

Pilot Jet: 50

PAJ: stock

Leak Jet : stock

Starter Jet: stock

Fuel screw (turns out): 2

Needle Model/Clip position: JD Red #4 clip from top

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: No-Toil

Exhaust Brand: YZ 450 2005

Average Altitude: 4000 to 6000

Average Temperature: 60 - 80

Average Humidity: low

Degree of Satisfaction (0-10): 9

Additional Mods/Comments: the bike came with 160mj and bike seamed too lean. The 165 mj is better than the 160 for sure. Bike starts great. I put in the powernow and powernow plus and low end is great now(much more responsive). Now I have a stutter while riding down the road at neutral throttle.

Year: 2002

Model 426

Cam Timing (WR/YZ): WR

Main jet: 165

Pilot Jet: 65

PAJ: stock

Leak Jet : stock

Starter Jet: stock

Fuel screw (turns out): 3.75

Needle Model/Clip position: std

Grey Wire Mod (Y/N): N

TPS Connected (Y/N): Y

Airbox Snorkel/Lid (on or off): off

AIS Removed (Y/N): N

Airfilter Brand: Stock

Exhaust Brand: GYTR

Average Altitude: 1500m

Average Temperature: 20-38 Celcius

Average Humidity: low

Degree of Satisfaction (0-10): 8

Additional Mods/Comments: When I got the bike it was idling high, until I turned the idling mix screw from 3 to 3.75. Got it idling very well.

Also down to 3 kicks with choke after 4 weeks. Hot, it starts 1 - 2 kicks.

DO NOT TOUCH THE THROTTLE WHILE KICKING!! :mad:

Cost me about 4 plugs to TRULY understand what that sentence means...

I've done about 300 km on the current plug, no hassles :mad:

Model : 2004 WR450F

Cam Timing (WR/YZ): WR

Main jet: 165 (stock was 160, this is a Canadian Bike)

Pilot Jet: stock, 45?

PAJ: stock

Leak Jet : stock

Starter Jet: stock

Fuel screw (turns out): 1.5

Needle Model/Clip position: blue JD #3

Grey Wire Mod (Y/N):N/A (Canadian, no grey mods to do)

TPS Connected (Y/N):Yes

Airbox Snorkel/Lid (on or off):Never a snorkel, (Canadian)

AIS Removed (Y/N):N/A

Airfilter Brand: OE

Exhaust Brand: FMF Powercore4 with quiet core insert

Average Altitude:500-3000

Average Temperature:45-70

Average Humidity:80%>

Degree of Satisfaction (0-10): 9

Additional Mods/Comments: none

Year: 2006

Model (400 - 426 - 450): 450

Date:11-6-06

Cam Timing (WR/YZ): WR

Main jet: 160

Pilot Jet: 42

PAJ: stock

Leak Jet : stock

Starter Jet: stock

Fuel screw (turns out): 2

Needle Model/Clip position: Adjustable Needle that comes with GYT AIS blockoff kit. #3 position.

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: Uni with Bel Ray oil

Exhaust Brand: FMF Q

Average Altitude: 5900 - 12,000 feet

Average Temperature: 40-90' f

Average Humidity: low

Degree of Satisfaction (0-10): 9

Additional Mods/Comments: I havent cut out the air box side on the right yet. The bike is very responsive, does not stutter or bobble and runs smooth. I may put a 162 in for MJ to see if I get a gain from it. I had a 45 PJ in and it had a bit of a burble in the lower throttle range.

And, I ride at higher altitudes (usually over 8000feet) and I hate the RICH burble you get from using Indy's chart. I find this bike is sometimes jetted too rich by various peoples advice for high altitude, just like the YZF forum.

Best thing is use these values as baselines and fine tune for your tastes and conditions.

Year:2007

Model (400 - 426 - 450):wr450

Cam Timing (WR/YZ):wr

Main jet:170

Pilot Jet:48

PAJ:

Leak Jet : stock

Fuel screw (turns out):2

Needle Model/Clip position: 07yz/3rd

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 ( comes with jets)

Airfilter Brand:stock

Exhaust Brand:stock pea shooter removed

Average Altitude:1200

Average Temperature:80

Average Humidity:

Degree of Satisfaction (0-10):10

Additional Mods throttle stop opened up. this bike rips with the stock pipe.:worthy:

Year: 2007

Model: WR450F

Cam Timing: WR

Main jet: 168

Pilot Jet: 48

PAJ: 70

Leak Jet : 50

Starter Jet: 70

Fuel screw (turns out): 1.25 Zip-ty

Needle Model/Clip position: JD red /#5

Grey Wire Mod: Yes

TPS Connected: Yes

Airbox Snorkel/Lid: Off

AIS Removed: Yes

Air filter Brand: Stock (hole plugged)

Exhaust Brand: Stock w/PMB insert

Average Altitude: 2500

Average Temperature: 75

Average Humidity: 15

Degree of Satisfaction (0-10): 10

Additional Mods: Richen the starter jet for hard starting at 2500'. Throttle stop screw shortened 12 mm (18.2mm from shoulder to tip). Steed wheelies with ease in 1, 2, 3 gears with the stock muffler and PMB insert. Very good throttle response, good for SoCal desert. Made my own AIS block off plate. :thumbsup::devil::smirk:

Year: 2002

Model (400 - 426 - 450): WR426F

Cam Timing (WR/YZ): WR

Main jet: 170

Pilot Jet: 42 stock

PAJ: 75 stock

MAJ: 200 stock

Leak Jet : NA

Starter Jet: 65 stock

Fuel screw (turns out): 1.5

Needle Model/Clip position: Blue JD needle 3rd position

Grey Wire Mod (Y/N): Y

TPS Connected (Y/N): Y adjusted to specs

Airbox Snorkel/Lid (on or off): off

AIS Removed (Y/N): NA

Airfilter Brand: UNI

Exhaust Brand: WB E2

Average Altitude: 0-1000

Average Temperature: 60

Average Humidity: 80

Degree of Satisfaction (0-10): 9 :bonk:

Additional Mods/Comments: Thin JD O-ring used on accel. pump linkage

Lots of low-end grunt and power everywhere on the RPM range.

No more hesitation or missfiring at cruising speed (TPS adjustment fixed that)

Year: 2007

Model (400 - 426 - 450): WR450

Cam Timing (WR/YZ): WR

Main jet: 170

Pilot Jet: 48

PAJ:?

Leak Jet : STOCK

Starter Jet: STOCK

Fuel screw (turns out): 2

Needle Model/Clip position: YZ 2nd DOWN

Grey Wire Mod (Y/N): N

TPS Connected (Y/N): N

Airbox Snorkel/Lid (on or off): OFF

AIS Removed (Y/N): Y

Airfilter Brand: TWIN AIR

Exhaust Brand: STOCK MODIFIED with GYTR insert

Average Altitude: SEA

Average Temperature: 10-40 CELCIUS

Average Humidity: 50%

Degree of Satisfaction (0-10): 9 With jetting 10 with bike

Additional Mods/Comments:

Everything is now crisp as!!

Looks

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