I finally got my 00 WR to idle with YZ timing I have a DSP pipe air box lid removed and I had to go to a 52 pilot to stop the back firing on deacceleration I have a little sputering at 1\3 throttle it may be the dvr needle which I have in the 5th clip position with a 180 main this is quite a bit off of the 48 pilot and 3rd or 4th clip position that most of you recomended I have a dvp on order any thoughts on my set up would be great. Im in Canada around the Great Lakes about a 1000 feet above sea level. THANKS

When I richen everything up to the point where the minor poping on decelleration is completely eliminated it is too rich and I loose snappy throttle resopnse. I'm running a 48PJ with 1.25 turns on the fuel screw a DVP #4 and a 182MJ. This is with WB CF Promeg and 15disks, and FMF PC IV-2. It pops on decelleration especially when comming down from WOT but response is excellent. 99WR400 with YZ timing. I use this jetting from 800 to 4000 ft. altitude.



Your 1/3 throttle sputter will not be cleaned up by the DVP alone. The clip position should be moved to #4 or #3. Same as Clark said for the DVP. The DVP is richer on the straight part and it's taper starts a little lower, after that they are identical.

I also found the #50 too rich and went back to a #48 on my 00WR400 which may figure into this also. (WR timing, stock pipe baffle out)

James Dean

I started with a 48 pilot and I couldn't get it to idle it backfired loudly on deacceleration and my plug was white if I let it just kept it running at low rpms (it wouldnt idle) then I went to a 50 pilot and when I went 3 turns out on the screw it started to idle but still popped quite badly so I then went to the 52 2 and a 1\4 turns out and it idles it still pops but not so bad unless from WOP so I just dont understand why my bike seems so lean to begin with and other thoughts? Thanks

Hey there Chris,

I have the DSP pipe and header and all the bits and pieces removed. I am running the WR pin on the 4th clip, 48 pilot and 160 main and fule screw 2 to 2.5 turns out.

It runs perfectly at the same sea level as yourself......


I suspect a air leak somewhere. Kinda sounds like Harry in Oz when he was running so rich and found a cracked hose on his hot start circuit. I'm kinda stumped unless there is an air leak somewhere getting into the intake tract or the carby.


Good call Clarke.

I did not think of that.

This sounds like a possible vacuum leak somewhere. See Clarks comments under "Hey Clark". Maybe check the float level, something doesn't sound right... anybody else using a #52 pilot jet???

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