What happened to the Jetting sticky ?

7 replies to this topic
  • FOZZ

Posted January 01, 2007 - 09:21 AM




MOD please delete my retarded post..

  • MountainMax

Posted January 01, 2007 - 10:45 AM


lol :lol:)

  • FOZZ

Posted January 01, 2007 - 12:39 PM


Guess its not a sticky no more :=()

should be though...

  • Fullbore4

Posted January 01, 2007 - 12:53 PM


I would give a dollar to one of the guru's like JD or Indy or someone else to write up a complete jetting tutorial for the WR450 so ALL the critical points would be in one place as I find my WR hard to get just right. Erin did a good job but it is so basic and doesn't elaborate on what exactly to feel, hear or see whether its rich, lean or indifferent.

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  • FOZZ

Posted January 01, 2007 - 01:36 PM


Hell ya man - me too...

A few things I would like to see..

1. YZ to WR parts match (compatible parts / year)

2. Advanced Carb Mods ( AP / BK / ACV) ???

  • clark4131

Posted January 01, 2007 - 06:59 PM


Much of the wizardry behind jetting comes more from experience and experimentation than anything else, it's more art than science. If you look in the .pdf European version of the manual, it gives you a nice chart that shows what jet is active respective to throttle position. If you feel unresponsiveness at a certain throttle position, then you'll know what jetting circuit is likely responsible and can adjust accordingly. Also, there is quite a bit of info on what has been asked for on ThumperFAQ, i.e. the BK mod, ACV, etc. Lastly, when it comes to jetting in general, TT has the jetting forum run by carb expert Eddie Sisneros, AKA Burned. James Dean also frequents that forum and is obviously another guru.

As each bike is often subtly different due to small manufacturing variations, as well as the infinite combinations of aftermarket parts, there is no definitive algorithim to follow. Unless you have a mechanic on staff, it really pays to learn your bike and diagnose it yourself. All the advice in the world means very little when you're in middle of the woods with a bike that won't idle and no wi-fi access. Indy's chart is the best thing out there to get you in the ballpark. Beyond that, a rider has to know his bike and whether the sputter at 1/2 throttle is better remedied with the Red or Blue needle, a different clip position, a larger pilot, a smaller main, or if you just have bad gas. Depending on the bike, the temps and the elevation, it could be any one of those, or a combination. Carb tuning is truly tedious, but once you get it down, you're golden...SC

  • Fullbore4

Posted January 01, 2007 - 08:07 PM


Yah for sure Clark.....I agree with a lot of what you say.

I use my 18 year old as the judge and jury when I make big changes.......he gets a real kick out of the power it cranks out.....he's 155 pounds and I'm 235. He's also pretty sensitive to details and lets me know of anything that doesn't seem right.

But you are right in saying there's infinite mods on these bikes and that is why I don't understand why folks on here recommend specific jet sizes for instance, when the guy inquiring doesn't know what jets are in it, what mods have been done or hasn't even tried riding it.

I think you would agree though that the infinite wisdom of some current posters and a LOT of posts from the past could be condensed and put in a certain spot. Maybe you moderators could make a new place for info that you all deem is adequate for keeping and put it there...I'm not refering to a new sticky for each topic...perhaps a catagory called WR400/WR425/WR450 /Keepers......just an idea.........anyway how much do you get paid.....JUST KIDDING......thankyou for doing a great job.

  • FOZZ

Posted January 03, 2007 - 07:33 PM


Thanks for your efforts w/ the info..

Being new at jetting bikes & with the complexitys of the new hi-tech carbs of today I have decided to just remove the DynoJet Wide Band off my R1 & get a bung welded into my header so I can (cheat) & see EXACTLY what my AFR is running & make changes from that..



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