help with the pop pop pop when deaccelerating


3 replies to this topic
  • cdkrv

Posted February 13, 2006 - 04:10 PM

#1

Just put on a white bros. w2 and trying to get rid of the pop. Had a t-4 on it before and it popped even worse. need some suggestions

  • Matty05

Posted February 13, 2006 - 04:13 PM

#2

Just put on a white bros. w2 and trying to get rid of the pop. Had a t-4 on it before and it popped even worse. need some suggestions

Use a bigger pilot jet and get an adjustable fuel screw.

If this is your problem, I recommend you look at the rest of your jetting, there is big gains to be made!

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  • freestyle250

Posted February 13, 2006 - 04:19 PM

#3

Agreed, jetting is huge. Check through the forums and see if anyone else in the forums have the same kind of setup as you, and are riding at the same elevation and what not. I rejeted my WR after removing AIS and the difference was definitely noticeable. and yes, the fuel screw is huge too, very easy to fine tune.

  • Matty05

Posted February 13, 2006 - 04:28 PM

#4

Here is indy's jetting chart, it is an awesome starting point!

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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