2008 Wr450 Jetting


36 replies to this topic
  • BOBR

Posted December 17, 2007 - 12:59 PM

#1

I picked up my 08 WR450 on Sat. along with the GYTR kit and it came with a 175 main jet and a 50 pilot jet. From everthing I've read on here it looks like the 07's all came with a 170 main and a 48 pilot...

That seems to be a fairly substantial jump in jetting from one year to the next with no reall changes to the bike other than BNG's.

A little help?

  • clark4131

Posted December 17, 2007 - 01:35 PM

#2

Peruse the jetting database to get you where you need to be...SC

  • BOBR

Posted December 17, 2007 - 02:11 PM

#3

Done that, which is why I'm asking here because of the difference.

  • garr87v

Posted December 17, 2007 - 03:25 PM

#4

My gyrt kit for my 07 came with the 50 pilot jet. I'm around 3500 feet and I think its a little rich. The 175 main jet works and I have the needle in the 4 position. I have a friend that is running the 48 pilot and he says its perfect for our elevation. He used the JD kit and the gyrt kit. I think the JD kit comes with the 48. I hope this helps.

  • BOBR

Posted December 17, 2007 - 03:39 PM

#5

Thanks for the response. If it weren't such a pain in the ass to change the jets I wouldn't even care but it is sort of labor intensive for such a simple change.

  • clark4131

Posted December 17, 2007 - 06:49 PM

#6

Your best bet is to default to this board. I know it sounds arrogant, but we do know what we're doing, most times better than Yamaha. When in doubt, TT is the definitive source. Keep in mind, the WR and YZ board is what started TT way back when...SC

  • JSanfilippo

Posted December 17, 2007 - 09:18 PM

#7

I have an '07 and the jetting is this

Everything is stock except
Main Jet: 165
Pilot: 48
Needle: JD Red in 4th position
Fuel Screw: MSR 1.75 turns out (1.25 in summer)
Exhaust: Stock w/pmb performance insert
Airbox: Took off snorkel, mounting bracket, and that support plastic thingy (basically as open as can be w/out cutting out the battery tray)
Misc: O-ring mod on AP

Bike pulls cleanly. It runs its best around 2000-3500 feet. It runs hair rich above 5000 feet and it runs a hair lean at sea level. Since most of my riding is 1500ft-4000ft I've just decided to leave it be. If I ever decided to run an aftermarket muffler a 168 will be more than plenty.

BTW stock was a 162 main/45 pj combo with the non adjustable smog needle

  • C-P

Posted December 17, 2007 - 09:41 PM

#8

I'm in the same position - rejetting my new '07 and not wanting to go through a ton of trial and error to do it - the most popular combo on the jetting board seems to be 168/48. Many say the GYTR kit is too rich. Also, there's a ton of needle and jet options to choose from if you go to the YZ parts diagrams. For the WR, not so much. Or just go JD.

  • Humunn

Posted December 18, 2007 - 05:23 AM

#9

Done that, which is why I'm asking here because of the difference.


I'll give you my perspective. I have an 07 and was asking the same exact questions and getting the same exact answers as you. The problem is no two bikes (or conditions) are the same. Just because a certain jetting combo works for one bike does not mean it will work for you and it is a big pain to guess.

If you get lucky and find something that works then awesome. Maybe you'll only have to tear into it once or twice.

I decided to just take mine into the local shop with a dyno. They analyzed the complete throttle range and I found that my bike was way rich, which was set up based on recommendations of others. I generally understand jetting but no way to the level required to make sure each of the jets is sized correctly and works together with the other jets to supply the right amount of fuel at the right time. They also had access to a company in Cal that specializes in WR and YZs so the parts were all tested ahead of time. It's all about information.

Bottom line is I walked out with a bike that was tested and adjusted based on hard numbers not guess work or what worked for someone else. I left $160 there and couldn't be happier. Saved me tons of time and frustration.

Hope this helps.

Greg

  • isobareng

Posted December 18, 2007 - 05:39 AM

#10

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  • Looks450

Posted December 19, 2007 - 01:40 AM

#11

I decided to just take mine into the local shop with a dyno. They analyzed the complete throttle range and I found that my bike was way rich, which was set up based on recommendations of others. I generally understand jetting but no way to the level required to make sure each of the jets is sized correctly and works together with the other jets to supply the right amount of fuel at the right time. They also had access to a company in Cal that specializes in WR and YZs so the parts were all tested ahead of time. It's all about information.

Bottom line is I walked out with a bike that was tested and adjusted based on hard numbers not guess work or what worked for someone else. I left $160 there and couldn't be happier. Saved me tons of time and frustration.


I have been looking for that in Australia, but all i can find is a dyno that tells Hp and torque. I am after one that tells me the fuel/air mixture through the rev range so that i can tell where in the circut needs atttention. What jetting did you end up at after all that?

Cheers
Looks

  • neema

Posted December 19, 2007 - 02:54 AM

#12

I picked up my 08 WR450 on Sat. along with the GYTR kit and it came with a 175 main jet and a 50 pilot jet. From everthing I've read on here it looks like the 07's all came with a 170 main and a 48 pilot...

That seems to be a fairly substantial jump in jetting from one year to the next with no reall changes to the bike other than BNG's.

A little help?


i'm in the same situation as you. i haven't thrown on the gytr kit yet, but what makes me feel a little better about throwing on the (substantially) fatter jets is that i'm throwing on a different air jet and leak jet, which may make the large jets seem not so large anymore... we'll see. if they do seem too fat, i'll make sure to post and let everyone know. as of now, i plan on running this with the intake silencer and pea shooter/muffler restrictor out.

just my $.02

  • BOBR

Posted December 19, 2007 - 11:38 AM

#13

I went with the all the other jets that came in the kit but I went with the 48 pilot & 170 main. I'll be trying it this weekend for the first time so I'll report back after the weekend.

  • Humunn

Posted December 20, 2007 - 05:59 AM

#14

I have been looking for that in Australia, but all i can find is a dyno that tells Hp and torque. I am after one that tells me the fuel/air mixture through the rev range so that i can tell where in the circut needs atttention. What jetting did you end up at after all that?

Cheers
Looks


Keep in mind I haven't ride tested this yet but here's what I have.
Elevation as tested 3500 feet.
Pro Tech jet kit
160 MJ
NDJN needle #2
100 air
42 pilot
72 starter
0 on the leak jet (blocked off)
1.75 fuel screw

If you want to order the parts or talk to the shop that did the work call Matt at Sage's in Bend, Oregon. Great guy. His number is 541.389.3478.

Greg

  • neema

Posted December 21, 2007 - 12:02 AM

#15

just finished the ais kit tonight... it's a little late so i didn't ride around the block, but it started up good and revved fine when it warmed up. the bike was definitely a PITA to work on. maybe it just an 08 thing, but the block off plate was impossible to get on because of the hex head that has a big coolant line in the way. regardless, i got it done, even though it too 10x longer than i thought it would.

big desert trip coming up this weekend so i'll give the heads up on how the bike runs when i get back. happy holidays

  • BOBR

Posted December 26, 2007 - 11:36 AM

#16

Did my first ride on the new scooter this weekend and from the initial crack of the throttle the power is way better than my 06'. The jetting seemed to work fine with no flat spots anywhere that I could find. Handleing was good and so far I'm really impressed with the bike compared to my last one. :banghead:

  • Idaho450

Posted January 12, 2008 - 09:12 AM

#17

I've got an '07 that is jetted the same as yours. I saw a big drop in mileage when I put in the JD kit, like in half. That can't be right. Did you see that?

I'm thinking I've got something else going on and am losing gas while riding.

Any thoughts?

Thanks,

  • camaroman7d

Posted January 12, 2008 - 10:34 AM

#18

Well I read the whole jetting and mods posts. I see what many people are using seems like 170 main and 48 pilot. My bike is an 07 which is the same as an 08 for the most part. The GYTR AIS kit is the same 175 main. I was wondering the same thing as you. Have people actually installed the complete kit and found it to be to rich and that's why they are going to the 170/48 jetting? Or are people just going straight to the 170 without installing the complete kit? I know riding location and conditions will vary. I have my bike apart right now and have the GYTR kit on hand. I don't want to do this more than once if I can help it (what a pain). I'm just reading and waiting for some info so I can proceed. If I need to go buy a couple jets no big deal.

The data base is great and I did read it all. I just don't know what other things were tried before settling on a given jetting. What I mean is did they try the 175 or not? Did they install the rest of the kit? Is the kit even needed? If I install the needle, throttle stop, air screw, do I just need to swap out the main and pilot (170/48) and leave everything else stock? If so no problem, I just didn't see that anywhere.

  • C-P

Posted January 12, 2008 - 07:29 PM

#19

Well I read the whole jetting and mods posts. I see what many people are using seems like 170 main and 48 pilot. My bike is an 07 which is the same as an 08 for the most part. The GYTR AIS kit is the same 175 main. I was wondering the same thing as you. Have people actually installed the complete kit and found it to be to rich and that's why they are going to the 170/48 jetting? Or are people just going straight to the 170 without installing the complete kit? I know riding location and conditions will vary. I have my bike apart right now and have the GYTR kit on hand. I don't want to do this more than once if I can help it (what a pain). I'm just reading and waiting for some info so I can proceed. If I need to go buy a couple jets no big deal.

The data base is great and I did read it all. I just don't know what other things were tried before settling on a given jetting. What I mean is did they try the 175 or not? Did they install the rest of the kit? Is the kit even needed? If I install the needle, throttle stop, air screw, do I just need to swap out the main and pilot (170/48) and leave everything else stock? If so no problem, I just didn't see that anywhere.


I'm in the same position...20 degrees and snow here, so my brand new bike is being torn down before I've even started it! Everyone seemed to agree the 175 main was too rich, even in the magazine tests. I bought the Yammy kit and 168 main/48 pilot because that seemed to be a good mid point to start at. I'd be curious to see how many people ran the GYTR kit as delivered and are happy with it.

  • WR450RICKO

Posted January 13, 2008 - 12:29 AM

#20

Put in the GYTR kit and take it to a shop with a dyno. Pay $100 or so and ride. I don't have any issuees with my bike running at sea level or up in around 4000 ft. No pop, no hesitatation good gas milage.
Do the free mods, gytr kit and dyno. You won't be disappointed.




 
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