what I did to my WR 450 today - and smart guy jetting question!?

:ride: The good news - my 2006 WR450 is now proud to be piped and free flowing!!!! Read all stickys RE: jetting and pipes and lists of what all you guys are running in your bikes. Many thanks to all of you for the Great info and experience from all of you, Thanks!!:rant:

What I came from: stock pipe, opened air box, GYTR AIS removal with GYTR 165 main jet and needle and a 48 pilot. 2 turns out. All other items are stock including air filter with Belray. How it ran was very responsive and right on the money through the entire powerband. Small amount of bog when riding singltrack at 15mph or less. Ran good at all temperatures and humidity from 0 to 4000 altitude (ran better in the 80-100 temp than in 50-70 but still adequate). Always hard to start though.

What it is NOW: FMF PowerCore with PowerBomb and quiet core, UNI air filter with NO-TOIL oil and very open air box, 170 main, JD Red #5, 48 pilot, 40 leak jet, ran best with 1 turn out of my zipty. How it ran in 65 degrees at 200 altitude close to ocean. Starts very easy. good response through whole powerband if I am not twisting hard. If I yank the throttle hard which is how I always ride, the first 1/8 throttle is good response and then 1/4 through 3/4 is not consistant and seems to be blotchy and boggy and a little bit of popping. 3/4 to full is pretty much the same.

My original thoughts were to tune it to 80+ degrees cuz summer is here and I ride mostly between 2000 to 3000 altitude inland in the mountains, not by the ocean. I went with what I did because of what I thought from reading my JD jet directions and from Indy 450 and others. I know my riding condition is now different than it is going to be at the 60 degrees and 200 altititude but should I start with dropping the 170 main to 168 or 165. I thought that since I had a 165 already before opening up my exhaust that I could afford to do the 170 - guess not. :thumbsup: Or should I change the eclip on my JD red to #4 position or move to the Blue #3 as seeming to be for all the winter riding?? Please advise on where and what I should do?? Thanks, Jason:confused:

That 170 is too rich. Go back to the 165 and you should be fine. Also, IMO, the 48 is too rich - I would go with a 45 with the red needle in the 5th notch.


Because you plan to ride at a higher alititude where the air becomes thinner you will need to go leaner on the jetting to compensate for that.

As you are having dramas between 1/4-3/4 throttle I would start with the needle moving it down a clip to # 4, then possibly # 3 if # 4 is not much of an improvement.

You might even need to go to a 162 or 160 main as well. I had the same deal when I added my GYTR race pipe, I went richer on the jetting from 165 to 170 and two days later had to go back to where it was, originally a 165. Finally I went to a 162 and that improved it further. Seemed weird to me but worked out great.

The small amount of bog when riding 15mph is probably caused your AP pump timing being slightly off.

Don't want to insult your intelligence but make sure you change just one thing at a time or it will be confusion city.

excellent!? anyone else.. I was thinking on that line about being wierd when I thought I should go up in mj size cuz I was letting triple the air through now with the new pipe over the stock pipe. Yes, daz, your right about the altitude, but my thoughts were that it was also colder now than it will be??? I didnt mention it in the above stuff. But I adjusted my AP timing to the open position of 2.7 mm (which is what the JD kit says) and used the thick o-ring. The AP was at approximately 1.8 mm before. Could this be a problem too?? I do agree that I need to do one thing at a time but that will be hard cuz my head is spinning and I want so bad to just twist and get it on. Thanks guys. I think I will start with just throwing the 165 mj in and seeing what it feels like - then maybe the 4th red position on needle. Anyone else and what about the AP timing?? thanks guys, Jason

ok guys, went out and tried the bike with the 165 mj and changed nothing else. It was 60 degrees and moist out. The bike strarts perfect and easy - through 1/4 throttle is good but not what I expected with the mods. 1/4 through 3/4 seems better but still is boggy. 3/4 to full seems to be the same. I did not change the 48 pilot to the 45 cuz I have to buy one as the 48 was on the bike already-installed with the AIS GYTR set up.

Do I change the needle next to 4th position or .........? Also, still want opinion on the AP timing. Did I adjust my screw out too much and am flooding my carb. I read on the AP 101 that it can make the bike boggy it is turned out too far, but dont know if that effect goes through the powerband. I know that I adjusted the AP about 3 turns out from where it was to get it to the specs on the JD jet kit directions!??

I need somemore opinions. thanks, Jason

The AP adjustment will effect response from just above idle, so if problems persist elsewhere in the rev range you can't cure it with AP adjustment.

If you take off the airbox boot from the carb and warm the bike up open the throttle as you would when riding and see if the squirt of fuel from the AP is clearing the carb slide or not, if it is not then the AP needs further adjustment.

Go out and get a 45 PJ then set up your pilot circuit as per the link below from Eddie the jetting man.

Then you can eliminate the PJ and pilot circuit from the equation - I would do this first as its the easiest to check.

If that doesn't improve things work, drop the needle to position 4.


I do agree that I need to do one thing at a time but that will be hard cuz my head is spinning and I want so bad to just twist and get it on.

I know what you mean, I'm laid up for 6 weeks after a knee operation :thumbsup: so TT helps relieve the boredom and I learn stuff too!

Check out this thread below for AP timing mainly from Barton, some really great info.

Your best bet might be to get the bike on the dyno and let a respected tuning shop do the hard work?



The popping you describe sounds like a lean condition but, the other conditions you describe make it sound rich. My opinion, you have already been on the leaner side of things so I would try the blue #3. As previously stated, get your pilot circuit dialed in first to eliminate that part. As the temps increase then you could go to the red #4 or 5. You should be good with probably a 165 or 168 at that elevation. Keep in mind that now your bike is breathing better it is more efficient and needing larger jetting is not always the case. Also, try the thin o-ring and see what that does if you still have a low end bog. good luck!

Hey guys, there is no low end bog now but I dont have the punch I though I would (could be explained from saying that I dont have as much back pressure?) I will pick up a 45 pilot cuz you guys are right - I am best at 3/4 to 1 turn on my zipty. When checking the AP timing are you checking the squirt when the bike is running - my manual seems vague on the AP circuit. I'll ride it again after those two items are done and then see if I need to adjust my needle. I have the 40 leak jet now - that seem ok with you all? The popping I think is insignificant and the bike is definately fat right now - I also didnt descibe this earlier but it seems to flatten out when I go full throttle fast. I will let you know - Dont know if I can get a test ride in tomorrow though. thanks again to all you guys. This site is great and I have passed it on to other fellow bikers. Give you results when I get them, Jason

Does your bike stall when the fuel screw is turned all the way in? If not, then that is a good sign that you are too rich on the pilot circuit. Since you said that you don't have a bog on the bottom then you are probably really close. As far as the low end snap, you may just be used to a yz or somethink with a lighter flywheel weight. I think that I may see a yz cam in your near future.

Hey Max, agreed on the snap part. I have been latent in the motorcycle field for 15 years - I was a two stroke junky and, well, have no strength or endurance any more and this bike makes my whimpy state look as though I still got it. Boy do I love my WR!!! NO I cant do the yz cam cuz I do a lot of slow technical stuff too. I just need a well rounded bike. I just thought that I would have gotten a little more with the mods than I am. My bog is gone on low end with the 40 leak jet and redueing my AP timing but am concerned that I didnt do it right cuz I didnt do it by visual squirt inspection. The bike falters when zipty is in all the way and runs best at 3/4 out. I am installing the 45 pilot after I get off this site and readjusting my AP sqirt. Unfortunately the weather again is wet and cold today, which is more like a winter weather than the summer weather which should be here -thought it was after last weekend, ....... Jason

The cam will not take away the ridability of your bike. It will just give that little added punch that it sounds like you are missing. I ride Kennedy Meaqdows(very technical at times) at 8000' with no problems. I assume that you have shortened the throttle stop and pulled the grey wire. If not, it's a must. Limiting yourself to 3/4 throttle could get you into more trouble then having full throttle to get yourself out of it

Hey Max,

I hear you on needing the entire throttle capability and believe me - I use all of it. I am always WOT (wide open throttle) from slow to fast. I was just under the impression that with the yz cam you have starting issues and then a more touchy and sensitive low end closed to 1/8 throttle!?? I went up to Kennedy Meadows last year with my original settings (see first write up on this page) and went 22 miles and had to fill up again on gas. I think the guy behind me got sprays of gas on him everytime I hit the throttle (haha!) Beatiful country up there - might try to do it again this year before summer hits. This time I'll be tuned for it though!

Hey Daz,

Hope your knee gets better - when you can - start doing range of motion excersizes to increase blood flow. That will push out toxins and scar tissue and inrease spead of healing by bringing in more nutrients to your injured tissue. Eat good balanced meals and no heavy smoking and drinking as this has many adverse effects on healing.

As to someone putting my bike on a dyno - A respected tuning shop - maybe if I could find one. I go down to the dealers and ask their mechanics questions and find that they cant answer the questions I ask. Much better to ask guys with a passion for what they do than someone that just earnes a dollar for twisting a wrench. I find that it all trades though. I know there are good honest hardworking trustfull people out there but they are scarce - so as I stated I trust in people with a passion about what they have and do and that is a value in this web site. Happy healing. Jason

I think that the guys who had starting issues used the yz/wr hot cams. I don't think the stock yz cam will cause you any starting problems. I'm sure there are a bunch of guys out there that can confirm this either way. The heavier flywheel weight still out weighs the impact of the cam. Usuall hit kennedy 2-3 times a season. Yes, it's awsome country up there. I'll PM you when we go up the in June. As far as a respected and trusted shop, Tokyo Mods in San Juan Capistrano. They are very meticulous there. I belive his name is Ron Woods.

Hey SXP, Max, and Daz,

Ok, changed my stuff around for trial and error. 170 main, 45 pilot, #50 leak jet, blue needle at #3 from top, AP squirt cant hit the slide when turned in or out. Duration is dont know now, but was app. .8 seconds with the #40 leak jet. Its problably close. My timing adjustment is as recomended by JD jetting (I called and talked with them re my situation). That is 2.75 mm. When I turned the screw out 1 full turn from there it seemed to be a little better on response but still has hesitation.

HOW did it run - Not compleetely sure cuz I dont have a place to ride it around alot. It had ok bottom from 0 - 1/8, It had good hit from 1/8 to 1/4, It had ok 1/2 to 3/4 and full but seamed to flatten out and loose my power when WOT. Dont like that cuz thats the position I am usually in - I ride my bike like a 2strke. I am trying things on the rich side of things to see if that works better without hurting my engine. Any ideas??? Jason

Not sure if it's safe to respond since your last "I'm pissed" post. Sounds like you are closer than before though. Maybe go to 168 main. Remember that you'll usually have a bog(hesitation) with the bike on the stand and no load on the motor. I think as we transition into summer then you'll be able to switch to the red needle.Maybe consider the dyno tuning avenue so that way if it is not running correctly then the blame is on someone else.

Going to do a real trial right now with my family at Ballinger Canyon. Let you know how it is on Saturday. Jason

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