1st 05 yz450 ????

3 replies to this topic
  • ncmountainman

Posted May 23, 2005 - 06:52 AM


ok i've almost gott'er dialed in. put the powerbomb/powercore 4,power now(rear one),icat,boyesen ap cover,set the ap timing,went to DWR needle(4th clip),48pj 170mj . there is a slight miss from 1/8th throttle to just past 1/4. its there at steady throttle and when 1st grabbing more throttle. it was there before the needle change and the leaner needle seemed to make it worse,its there with or without the tps disconnected,so i'm guessin; i need to go to the 5th clip? i know the p-now leans the pilot circuit a little and then the leaner needle didn't help,but it doesn't pop on decel like my wr did when it was lean on the pilot and turning in the fuel screw seems like it makes it worse as far as the miss but will not produce the decel popping even with it down to one out? top end is fine over 1/2 throttle. any suggestions? btw i changed to that needle to help with bottom end response(which it did) :)

  • ncmountainman

Posted May 23, 2005 - 09:58 AM


well i went to the 6th clip w/the 48pj; man was that the wrong direction :eek:was barely running between 1/8 and 1/4 throttle, so i'm gonna try going to 3rd clip. i thought from the get go it may have been to rich but i thought cutting out was a lean condition? but then again thought one thought he farted but $hit himself :) so temps are in the 70's,humidity 70%,elev 2500'-3000',any idears or am i on the right track?

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  • ncmountainman

Posted May 23, 2005 - 11:02 AM


well if someone would've told me to try this combination i'd of probly laughed,but here goes: 40pj,170mj,DWR needle, 3rd clip. runs perfect,just starting to pop on decel @ 2 turns out.its getting hotter here so thats a good place to be for now. man and here i thought this bike would need to be richer than the wr,it must be the lower compression,or less cam duration or sumthin. just glad i got it figured out. thanx for listening :)

  • MotoGoalie

Posted May 23, 2005 - 11:07 AM


I just read this.

I'm a 4 stroke newb basically, but I recently found out that really rich jetting on the PJ mimicks lean jetting and creates all kinds of popping and surging nonsense too. Backfiring I guess.

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