Not the results I expected (Jetting)


10 replies to this topic
  • BNutZ

Posted May 02, 2005 - 08:51 AM

#1

I rejetted my 05 WR450F yesterday and was not overly excited with the result. With the way everyone talks on here, i expected the bike to pull a lot harder and be a bit snappier. The bike is still tough to start (must turn the idle up) and dies if the throttle is wicked open quickly. Comments / Suggestions on maximizing my jetting would be greatly appreciated.

Current setup as follows:

Cut Throttle Stop
Cut Grey Wire
AIS Removal Kit
Removed Exhaust Silencer
Removed Airbox Snorkle
Zip Ty Fuel Screw - 2 out.
JD Red Needle #5 (counted from the top down, 1,2,3,4,5 - correct?)
168 Main Jet
48 Pilot Jet
All other Jets are Stock (can someone identify the other stock jet #'s?)

Current Temp: 65F (soon to be 90-100 with summer almost here).
Current Altitude: 361' ASL
Riding Altitude: 1500' to 4000' ASL

  • beezer

Posted May 02, 2005 - 08:58 AM

#2

I have a WB pipe on mine and the airbox opened up on the clutch side.

You may want to try the blue needle.

I would put a #72 starter jet in it and a #40 leak jet in it.

The richer starter jet will make it start easier and the smaller leak jet will make the bike less likely to flame out when you grab a handful of throttle.

My WR is fast so don't give up.

  • BNutZ

Posted May 02, 2005 - 10:12 AM

#3

beezer,
thanks for the response... i was thinking the 72 starter and 40 leak might help but reading Indy's posts, he recommends a smaller starter jet (68) in the hotter temps.....? Maybe the 72 on the 05 WR's is ok year round...?

Additionally, I'm thinking of bumping the main up to a 170.... last but not least, can someone answer my needle clip position and stock jet questions above?


Thanks,
R/Brandon

I have a WB pipe on mine and the airbox opened up on the clutch side.

You may want to try the blue needle.

I would put a #72 starter jet in it and a #40 leak jet in it.

The richer starter jet will make it start easier and the smaller leak jet will make the bike less likely to flame out when you grab a handful of throttle.

My WR is fast so don't give up.



  • DesertWR

Posted May 02, 2005 - 10:40 AM

#4

I rejetted my 05 WR450F yesterday and was not overly excited with the result. With the way everyone talks on here, i expected the bike to pull a lot harder and be a bit snappier. The bike is still tough to start (must turn the idle up) and dies if the throttle is wicked open quickly. Comments / Suggestions on maximizing my jetting would be greatly appreciated.

Current setup as follows:

Cut Throttle Stop
Cut Grey Wire
Removed Exhaust Silencer
Removed Airbox Snorkle
Zip Ty Fuel Screw - 2 out.
JD Red Needle #5 (counted from the top down, 1,2,3,4,5 - correct?)
168 Main Jet
48 Pilot Jet
All other Jets are Stock (can someone identify the other stock jet #'s?)

Current Temp: 65F (soon to be 90-100 with summer almost here).
Current Altitude: 361' ASL
Riding Altitude: 1500' to 4000' ASL


Don't put in the Blue-It's getting too hot for that. I just rejetted my bike with the JD Red # 5 (5 down from the top), 48 pilot, 40 leak & a 170 main. This actually cured my cold start problem-I have not changed the starter jet and my bike rips now. Have U taken off the AIS? That mod really helps the smoothness of the throttle and eliminated virually all of the backfiring and popping. If anything, I would change my main to a 175 but you may want to start with a 170 and see how she runs. Search the forums, there are tons of part #'s for the jets :naughty:

  • Ga426owner

Posted May 02, 2005 - 10:44 AM

#5

Stick with red needle for temps 60 - 100....Blue is under 60 temps
on the needle - clips numbers are from the top down
I use #3 and #4 for - Altitudes 900-2000ft
The 05 WR has a leak jet I believe you may want to try the different leak jet
- PM NCMountainman for his findings - this supposedly helps with the bog -
Try a 170 main but for hotter temps go to the 168

See if this helps -

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • BNutZ

Posted May 02, 2005 - 10:46 AM

#6

DesertWR - Thanks for the response....

I forgot to mention that I have the AIS Removal Kit installed... I installed the Red #5 because most of the posts I read suggested that needle/position as comparable to Blue #3.... red needle was more for warmer weather too which I'm anticipating. I think I'll bump the main to a 170 and order the #40 leak jet PN: 4JT-1494F-03 and see where we're at..

  • Dan_Lorenze

Posted May 02, 2005 - 10:53 AM

#7

I hear so many of you guys with problems using JD needles... Bnutz, your bike is practically set up just like mine except the needle, I've got an 04 WR needle.. My bike rips... It's spot on and I can't imagine it any better.. To me it sounds like your needle is in the wrong place..

The a 170 won't solve your problems, trust me on this, there's not a whole lot of difference between the 168 and 170. I also don't know how much the AIS hinders the whole jetting system, I can't imagine much.. Do your self a favor either move or change the JD needle or just throw in the stocker, it's fine... :naughty:

  • Fredneck75

Posted May 02, 2005 - 11:25 AM

#8

BNutZ - You have almost the exact same setup as me, except I have the pmb exhaust insert. Mine is pretty close, and starts just fine. I did order the #40 leak jet to see if that helps. When you are snapping the throttle, are you in nuetral or actually in gear? Mine will stall too if I am in neutral and snap the throttle from idle. If I am in gear I don't have any problem with it stalling. All I can say is try to play with it. I've changed the jetting about a dozen times already trying to get it just right. Good Luck.

  • MathProf

Posted May 02, 2005 - 11:37 AM

#9

I agree with Dan: It's the needle position, drop the needle down(raise the clip)

  • BNutZ

Posted May 02, 2005 - 12:19 PM

#10

Fredneck75 - I'm in neutral when snapping the throttle...

Dan / Math Prof --- I'll have to bump the clip on the JD red needle from #5 to #4 and see how that works for me...

BNutZ - You have almost the exact same setup as me, except I have the pmb exhaust insert. Mine is pretty close, and starts just fine. I did order the #40 leak jet to see if that helps. When you are snapping the throttle, are you in nuetral or actually in gear? Mine will stall too if I am in neutral and snap the throttle from idle. If I am in gear I don't have any problem with it stalling. All I can say is try to play with it. I've changed the jetting about a dozen times already trying to get it just right. Good Luck.



  • BNutZ

Posted May 13, 2005 - 09:45 PM

#11

Just finished rejetting tonight... bumped the main from a 168 to 170, added a 72 starter jet and a 40 leak jet. Bike appears to run a lot stronger... third gear wheelies are completely a non-issue... fourth gear they come up a ways under power... I took the airbox lid off the side and it seems as if I was getting fourth gear wheelies quite a bit easier......

my question to you all....... since I have the stock exhaust with the silencer completely removed (SA still installed), would it be wise to open up the airbox on the right (brake) side? Is this going to cause problems because the stock exhaust isn't terribly free flowing? What is going to happen when I put a more free flowing exhaust on...? Is the power gain going to be that noticeable?


Thanks,
Brandon

Current setup as follows:

Cut Throttle Stop
Cut Grey Wire
AIS Removal Kit
Removed Exhaust Silencer (not the baffle but the entire silencer)
Removed Airbox Snorkle
Zip Ty Fuel Screw - 1 1/2 out.
JD Red Needle #5 (counted from the top down)
170 Main Jet
48 Pilot Jet
72 Starter
40 Leak

Current Temp: 80F (soon to be 90-100 with summer almost here).
Current Altitude: 361' ASL
Riding Altitude: 1500' to 4000' ASL




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.