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snmhanson

2005 WR450 Jetting

4 posts in this topic

I have a 2005 WR450 which I have owned since new. The jetting has always been ok but not perfect. I just got a Boysen Quickshot II to help with the off-idle bog and now I want to really get the jetting dialed in. Here are the particulars:

All free mods done including grey wire, AIS, airbox, etc...

Boysen Quickshot II

FMF Ti Powercore

ZipTy Fuel Screw

JD Jetting Kit

Ride in Pacific Northwest from sea level to ~3,500'

Usually in 50+ degree temps but some sub-50

When I installed the Quickshot I rejetted with a 168 main, red clip @ 3rd position, 48 pilot and 68 starter with the fuel screw 1-3/4 turns out. It was too lean (as I figured it probably would be) and backfired alot when trying to start it. Also had a huge bog if I whacked the throttle. Before that I was using a 170 main and the blue needle @ 3rd position with the fuel screw 1-1/2 turns out. Ran much better but seemed a little boggy in general. I am thinking that going back to the 170 main and using the blue needle at 4th position with the fuel screw 1-1/2 to 1-3/4 turns out may be close but not sure.

Bottom line is I have a job, a business, three kids, a wife and not enough time experiment with my jetting. Can anyone give me the ideal jetting setup based on all of the info above. I would appreciate it VERY much.

Thanks,

Matt

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FROM THE JETTING DATA BASE:

Re: JETTING D-Base WR400/426/450

Here is what works for me and you guys can use it as a starting point to jet your WR450 bikes only!

(Note: do not use these for WR426 or WR400 due to carb differences!)

This recommendation requires air box flow mods and an open stock or aftermarket pipe and ACV circuit intact.

Elevation 0 to 4,000. feet

30 to 45 degrees: 172 main, JD Blue #5, 48 Pilot, 2.0 turns, 75 starter jet, #0 leak jet

45 to 60 degrees: 170 main, JD Blue #4, 48 Pilot, 1.75 turns, 72 starter jet, #0 leak jet

60 to 75 degrees: 168 main, JD Blue #3 or JD Red #5, 48 Pilot, 1.5 turns, 70 starter jet, #40 leak jet

75 to 90 degrees: 165 main, JD Red #5, 48 Pilot, 1.25 turns, 68 starter jet, #50 leak jet

90 degrees plus: 160 main, JD Red #4, 45 Pilot, 2.0 turns, 65 starter jet, #60 leak jet

Elevation 4,000 to 8,000 feet:

30 to 45 degrees: 170 main, JD Blue #4, 48 Pilot, 1.75 turns, 72 starter jet, #0 leak jet

45 to 60 degrees: 168 main, JD Blue #3, 48 Pilot, 1.5 turns, 70 starter jet, #40 leak jet

60 to 75 degrees: 165 main, JD Red #5, 48 Pilot, 1.25 turns, 68 starter jet, #40 leak jet

75 to 90 degrees: 165 main, JD Red #5, 45 Pilot, 2.0 turns, 65 starter jet, #50 leak jet

90 degrees plus: 160 main, JD Red #4, 45 Pilot, 1.75 turns, 65 starter jet, #60 leak jet

Elevation 8,000 to 11,000 feet: ( Note you will loose a lot of power due to altitude but your bike will idle and not foul plugs!)

45 to 60 degrees: 165 main, JD Red #5, 48 Pilot, 1.25 turns, 70 starter jet, #40 leak jet

60 to 75 degrees: 160 main, JD Red #4 , 45 Pilot, 1.75 turns, 68 starter jet, #50 leak jet

75 to 90 degrees: 158 main, JD Red #3, 45 Pilot, 1.5 turns, 65 starter jet, #60 leak jet

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FROM THE JETTING DATA BASE:

Re: JETTING D-Base WR400/426/450

Here is what works for me and you guys can use it as a starting point to jet your WR450 bikes only!

(Note: do not use these for WR426 or WR400 due to carb differences!)

This recommendation requires air box flow mods and an open stock or aftermarket pipe and ACV circuit intact.

Elevation 0 to 4,000. feet

30 to 45 degrees: 172 main, JD Blue #5, 48 Pilot, 2.0 turns, 75 starter jet, #0 leak jet

45 to 60 degrees: 170 main, JD Blue #4, 48 Pilot, 1.75 turns, 72 starter jet, #0 leak jet

60 to 75 degrees: 168 main, JD Blue #3 or JD Red #5, 48 Pilot, 1.5 turns, 70 starter jet, #40 leak jet

75 to 90 degrees: 165 main, JD Red #5, 48 Pilot, 1.25 turns, 68 starter jet, #50 leak jet

90 degrees plus: 160 main, JD Red #4, 45 Pilot, 2.0 turns, 65 starter jet, #60 leak jet

Elevation 4,000 to 8,000 feet:

30 to 45 degrees: 170 main, JD Blue #4, 48 Pilot, 1.75 turns, 72 starter jet, #0 leak jet

45 to 60 degrees: 168 main, JD Blue #3, 48 Pilot, 1.5 turns, 70 starter jet, #40 leak jet

60 to 75 degrees: 165 main, JD Red #5, 48 Pilot, 1.25 turns, 68 starter jet, #40 leak jet

75 to 90 degrees: 165 main, JD Red #5, 45 Pilot, 2.0 turns, 65 starter jet, #50 leak jet

90 degrees plus: 160 main, JD Red #4, 45 Pilot, 1.75 turns, 65 starter jet, #60 leak jet

Elevation 8,000 to 11,000 feet: ( Note you will loose a lot of power due to altitude but your bike will idle and not foul plugs!)

45 to 60 degrees: 165 main, JD Red #5, 48 Pilot, 1.25 turns, 70 starter jet, #40 leak jet

60 to 75 degrees: 160 main, JD Red #4 , 45 Pilot, 1.75 turns, 68 starter jet, #50 leak jet

75 to 90 degrees: 158 main, JD Red #3, 45 Pilot, 1.5 turns, 65 starter jet, #60 leak jet

Man, I can't wait until Yamaha comes out with efi...

Thanks for the reply. I have gone off of those numbers before but I wasn't sure if all my mods together might require different jetting than above. I was kind of hoping someone could give me a setup that will work well in most conditions so I only have to change it once per year.

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