WR 450, Is there a list of the free mods

11 replies to this topic

Posted October 07, 2003 - 07:04 PM


Is there a list of the free mods everyone is referring to somewhere on the site?

  • LarryCO

Posted October 08, 2003 - 09:30 AM



Offhand, I dont know of any place where there's a published list persay...just several other posts like this with folks asking about what mods they can do to their bikes...

Here's a partial list:
- Cut down the stock throttle stop (stock length only gives you about 1/2 throttle capability!).
- Remove the airbox cover (allows carb to breathe better...more power).
- Re-route the various carb vent lines into the airbox (helps keep water out of carb when bike is running and stuck in a stream).
- Cut the grey wire (you'll have to read-up on this one...didnt notice any improvement myself).
- Adjust the front and rear suspension to your riding style and weight.
- Change to YZ timing (helps power in mid to high end, sacrifices some of your low end...personal preference).
- Uncork the exhaust (if you're riding in a location that this is appropriate).
- "BK" mod (limits the amount of fuel being poured into the carb by the accelerator pump when opening the throttle...removes the low-end "bog" you most assuredly will have).

Now, some not-quite-free but definitely worth while improvements:
- Jet the bike correctly (2nd biggest performance improvement over shortening the throttle stop).
- PowerNow/JamesNow mod (helps with airflow into the carb from 0 to 1/2 throttle...good feedback on this one, but havent done it myself yet).
- Get rid of the stock tires and purchase some Michellin M-12's or Dunlop 756's.

That should get you thinking and keep you busy for a while. I suggest doing searches on each of the topics listed above that you're interested in. There's a wealth of information out here on this site. Also, dont be afraid to ask questions! :)

Good luck!

  • endurodog

Posted October 08, 2003 - 11:34 AM


Good list Larry. 1 thing to keep in mind that on the 450's changing the timing involves changing the cam, i.e. buying the YZ450 cam.

  • LarryCO

Posted October 08, 2003 - 12:51 PM


Right on.

How's my ol' home state doing? Enjoying that 80 degree weather are ya? I sure do miss it there... :) But MN isn't all that bad either... :D

  • Indy_WR450

Posted October 08, 2003 - 01:24 PM


Good list Larry, but the WR450 needs a new cam to go YZ timing $160. smackers. You do not need the BK mod on the WR450 carb either. :)

  • z4me

Posted October 08, 2003 - 03:46 PM


While not directly aimed at the 450, the 250F FAQ at http://www.thumperfaq.com/ has the details of doing most (if not all) of the mods mentioned. :)

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  • LarryCO

Posted October 08, 2003 - 04:26 PM


No accelerator pump mod required for the 450, eh? Nice. Why is that? Is it a different accel-pump, or did they actually decide to put in some sort of accel pump actuator-throw adjustment instead of having folks do it themselves?

$160 for YZ cams? Geez...I wouldnt be doing that mod either. Money's better spent on new tires, jets, hospital bills, and post-ride cocktails!

Anyhoo, check these mods out Bibmen and ask when you have a question. Again, from my viewpoint, throttle stop #1, re-jet the bike with YZ jets (or JD kit jets) #2, then the others as you see fit. Makes a WHALE of a difference...trust me. Different bike alltogether.

Good luck.


  • tctrailrider

Posted October 08, 2003 - 05:05 PM


One of your posts awhile back, you had ordered the JD kit. Have you tested it? If so how did it go. Are you getting to ride much in MN?


Posted October 08, 2003 - 09:49 PM


Thanks for all of the info. As you might expect I sent Michelins to the dealer and told him he could keep the Dunlops. I really like the Enduro Comp III, its shorter, tighter lugs and soft rubber work real well in hard pack and on rocks.

  • TWSimpson

Posted October 09, 2003 - 03:32 AM


Hey LarryCo,
How's your bike performing at that lower altitude? Notice the increase in power with a little more oxygen huh. Good to see your post.
Yep, 81 today, 80 on Friday. :D We're getting a cold front moving through on Saturday. :) Will lower the temps to the 60's but will be back up into the 70's on Sunday. :D Late fall this year, Aspens are just now dropping their leaves.
Take Care :D

  • endurodog

Posted October 09, 2003 - 05:17 AM


Colorado is doing good this fall, the weather is holding, the aspens are turning, and the riding is good this year. Hope your finding the same out there!!!

  • LarryCO

Posted October 09, 2003 - 07:24 AM


Nice guys...I'm definitely jealous!

Yeah, the bike's running VERY well with the jetting I've got now...and yes, more oxygen certainly helps! :) Got that JD kit...but havent put it in yet. Next weekend will only be the 4th ride of the season for me! Geez... :D Been working out of town during the week in CA, so time on the weekends has been scarce. Once I get a chance to try it out, I'll let ya all know how it compares with what I've got now.

On the positive side of things, we're renting a house right on the Mississippi River...so many a smallmouth bass has found their way onto the end of my fly line! And then there's CKULZER coaxing me to get studded tires so I can go ice riding once the lakes freeze...that should be interesting!

Anyhoo, things are going well...just not nearly as much time on the bike as I would like...but that'll change here soon I hope. Keep on riding Rampart/Georgetown/etc. before the weather gets bad and/or the next disgruntled forest service person burns it down!



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