jetting help guys with newr wr's...

11 replies to this topic
  • bomax

Posted November 26, 2005 - 11:05 PM


ok,i got my o6wr450 all free mods done,spark arrestor screen gonetc

been ridin it to work these last few days to jet it,its cold out.
30-40 degrees,sea level,100% humid.

tried alot of combos.

48 pliot/blue#3/170/11/2
48/red#4/170/1 1/2
48/blue#4/170/1 1/2
45/blue#4/170 1 1/2

hers the deal.the last set pulls like a darn beast and whales but at cruise ing with throttle barely open it studders/probly less then 1/4 throttle.when pinned its a bullit,theres no backfire on decel,and only bogs a hair when ya wack the throttle at idle but bareley just bareley..its a but harder to start as well with the 45 then the 48 in it(understandable)when i richen it all up it runs crappy period.

this is annoying as iam on the street,and its studers and hunts everytime there in every gear.

anything to look for guys?or try..the airscrew?

any recomaendations?iam wearing the screws out.

  • tony1970

Posted November 26, 2005 - 11:17 PM


Check the jetting sticky on top of this forum to match up what someone may have in similar conditions you are in. I had the same problem with a studder at about 1/8 to 1/4 throttle. I was too rich on the needle end and sounds the same for you. The red needle runs leaner so maybe try the red needle at a richer setting ,needle higher, but you are at a cold area so the blue should work. :applause: I had the 45pj in and it was hard to start hot also and the 48 helped with hot starts. Every bike is different so keep trying. Good luck.

  • Indy_WR450

Posted November 27, 2005 - 04:29 AM


The TPS feedback loop to the CDI is known to create a studder in street riding at steady speeds and partial throttle openings. Just disconnect your TPS for street riding or put a switch on her so you can turn the tps signal on and off to the CDI. :applause:
Hard to start put in a 72 starter jet for cold weather! Choke wide open no throttle easy cold starting! :ride:

  • rich1167

Posted November 27, 2005 - 08:27 AM


I re jetted with the JD kit and used Indys chart as a baseline. I only had to mess with clip position to dial it in from their. After I got it good and warmed up I noticed a miss at times on hard acceleration. I unplugged the TPS and it was gone.

I know this has been talked about in other therads and I don't want to hijack this one. But is their any adverse affect of running with it unplugged? :applause:

  • Dan_Lorenze

Posted November 27, 2005 - 09:04 AM


Bomax, I think your pilot and main are right on. What needle are you runnin and where's it at? I've had the most success when my fuel mixture's at 2 complete turns out. If you want to split hairs you could try a 168 main but I would make sure your needle is in the 4th position. Leave the pilot alone...


  • old man dan

Posted November 27, 2005 - 09:52 AM


Hi, I don't know where exactly you are in BC but I'm in Nanaimo and its about 8 or 10 Degrees here and I'm set up at 48 pilot- 2 turns on fuel screw- 168 main - LD blue 3rd- Promoto Billet tip with spark arrestor in place. The bike has never run better, no bog or sputter whatsoever, the cold air really makes a difference but I never have to hold a cruise speed ( dirt only). I have heard the sputter story a few times and the soloution seems to be disconnecting the TPS.

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  • bomax

Posted November 27, 2005 - 12:35 PM


iam in lower mainland,riding in the morning it was 2 degrees yesterday,damn cold.

i tried the red needle #4 with 48 pilot,170/1 3/4.was the smoothest but had the lean a lean hicup.

i currently have the blue #4/170,45 1 3/4 and it actually is really strong.

i will try your setup dan,but leave a 170 in it because iam on the street.

i will disconnect the tps as well.seams that could be the culprit.any adverse effects of that?

  • old man dan

Posted November 28, 2005 - 09:00 AM


I've never tried disconecting the TPS because I've never had a reason to but my understanding is that the ignition unit uses the TPS to correct timing for load and under very light throttle cruise conditions it gets "confused" and advances and retards the timing back and forth and causes the stutter condition. If you disconnect the TPS the ignition just ignores it and goes to a fixed curve.

  • Dan_Lorenze

Posted November 28, 2005 - 09:04 AM


I'm in Nanaimo

I've actually been to Nanaimo... Beautiful!!! I stayed at this place on the water where the restaurant was an old boat.. Had a great time!!! you're a lucky man old man dan... :applause: :ride:

  • dbailey223

Posted November 28, 2005 - 12:30 PM


From memory, didn't the posts about the TPS say that you lose a little engine power by disconnecting it? So, people on the road who wanted to avoid the surge would disconnect it, but then when they hit the dirt, they would stop the engine, reconnect it, and enjoy the added oomph?

  • old man dan

Posted November 28, 2005 - 03:44 PM


That sounds probable, the ignition probably reverts to a fixed safe curve with no TPS input. With the TPS the ignition can have a more aggressive curve using throttle position as a variable. If it was me I would have a switch in the circuit that I could turn on or off as needed.

  • bomax

Posted November 28, 2005 - 07:17 PM


ok i disc it and it smoothed out alot.theres still a hesitation a bit but this morning it was -1 out a frickin cold,i think a 50 pilot would do it,i have the 48 in it and pulled the airscrew to 2.5 out and it smooth it out.

i think iam asking to much from it with this coold weather.

i'll leave it for now.thankx for the advice...


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