Post Your WR426 Project!

Yamaha WR426F Yamaha WR426F 2001

13 replies to this topic
  • aj1208

Posted March 26, 2015 - 10:11 AM

#1

Anybody with a current/past WR426 project please feel free to post your progress here. 

 

I'm in the process of restoring my 2001 WR426 and getting it street legal; I paid $1600 for the bike and so far have put about $486 into it. If anyone has questions about the street legal process or the parts needed just ask below. 



  • nilknarf

Posted May 13, 2015 - 10:12 AM

#2

Good timing! I just picked up an '01 WR426 for $750- the previous owner warned me that it was going to be a big project, and he was right!

 

Here's what I know so far:

  • The cam journals in the head are peened so badly that I can't get the buckets out of the head to change shims (and there's no clearance under 4 out of 5 valves) I sourced a steel-valved head from a 2000 yz426 with good cam journals and I've got both heads all boxed up to go to Engine Dynamics in Petaluma, CA for restoration
  • The cylinder bore is scored, so I've got it all boxed up to send that off to US Chrome for restoration and mating up with a new Wosner piston.
  • The connecting rod has NO discernible bearing play, but rotates smoothly and freely (finally, some good news!)
  • The oil drain plug was/is stripped
  • The carb was full of water, so the jets were all hopelessly clogged with verdegris (that crusty green flaky stuff that forms on brass) so I have all new jets already installed
  • The swingarm bolt is stuck so tight that I'm going to have to cut it out with a saws-all (luckily, the engine does rotate on that bolt, so I should be able to tap it out once it's in pieces)
  • Both radiators were slightly crushed and leaking- I already have a new set sourced from ebay.
  • The front wheel bearings are shot
  • the chain/sprockets need to be replaced
  • The subframe is tweaked and the airbox has been slightly damaged in the same incident- I'm debating the idea of snagging an aluminum '02 yz426 subframe.
  • The plastic will eventually be replaced (already have new fork guards and yz rear fender)
  • The bark busters are bent beyond use- clutch and brake levers couldn't even be located to usable positions, so those are gone.

but I've heard enough good about the model that I can't wait to bring the old beast back to life! More power than my guest xr250, way less weight than my normal ride xr600. I'm hoping (against hope) that I might be able to get the bike plated, but I hear the chances of success here in Oregon are virtually nil.

 

Curt

Attached Thumbnails

  • IMG_1302.JPG

Edited by nilknarf, May 13, 2015 - 03:46 PM.


  • nilknarf

Posted May 14, 2015 - 02:06 PM

#3

okay- my heads and cylinder have officially left the building for their respective rescuers...

 

Curt



  • nilknarf

Posted June 28, 2015 - 03:20 PM

#4

Nobody else working on a WR426 these days?

 

Update on mine:

  • Swingarm and suspension linkage all cut off (all bearings and bushings rusted solid)
  • Frame all stripped and repainted (metallic charcoal VHT engine enamel), '02 swingarm installed w/ all new marine-greased bearings/bushings
  • Steering head bearings cleaned and re-greased
  • Cylinder back from replating by US Chrome, New Wossner Piston ready to install
  • Head back from Engine Dynamics with a complete SS-valves rebuild
  • New cam chain
  • Main bearing radial play measured and deemed well within acceptable tolerances
  • Stripped drain plug hole repaired (used an m14 steel drain plug drilled and tapped- and JB-welded in for an m10 plug)
  • '02 YZ subframe sourced, cleaned up and ready to install
  • 3.4-gal Acerbis tank on its way here, YZ seat awaiting install
  • Big platform pegs awaiting install
  • Oversize radiators awaiting install (sourced through ebay new)

 

That's all for now!

 

Curt


Edited by nilknarf, June 28, 2015 - 03:21 PM.


  • KOCONUT

Posted July 18, 2015 - 02:35 PM

#5

havent been on in awhile and just saw this thread.  Getting plates send in from South Dakota soon.  Just added a tusk enduro lighting kit and a trail tech vapor.  everything is working awesome.  When I bought it from the PO it was super dirty and looked like it had been rode hard and put away wet (literally, the rear master was seized) its whole life.  It did run and start well when I picked it up though.  Also added a renthal chain/sproket kit, new grips, and all new plastics.  Havent touched the engine yet.  It runs strong and havent had a reason to yet.  If I decide to hold onto it forever, I might go through the motor and have it rebuilt.  Then I could go through the frame and swap out all the bearings and get the frame re powdercoated.  



  • nilknarf

Posted July 21, 2015 - 07:44 PM

#6

Okay- with this one I'll try to stop hogging this thread... (right!)

 

Finally started the old beast for the very fist time since I've owned it and rode it around for just a few

IMG_1335_sm.jpg

Even with the pea-shooter stuffed into the muffler, it feels like it has twice the wheelie power of the ol' xr600 in the background with only half the weight- now I can't wait to get it broken in! Still have a few cosmetic mods to go over (new plastics, maybe some graphics) and then it's time to see if I can get some plates too!

 

Curt



  • Bubbles dog

Posted August 09, 2015 - 03:28 PM

#7

ImageUploadedByThumper Talk1439162357.654684.jpg

Just got my 1999 wr400f running,been sitting for 8 years,ccs racing suspension rebuild,kenda Parker desert tires,wheel bearings,new aluminum radiators,unibiker rad guards,jd jet kit,scotts fuel screw,new yz plastics,upgraded baja designs with led blinkers,trail tec battery. Engine was fine runs strong and was California plated.Replaced my Honda xr650l for dualsport it's now my road bike.

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

Posted August 09, 2015 - 03:29 PM

#8

Traded it for a cj5 jeep.

  • Bubbles dog

Posted August 09, 2015 - 03:30 PM

#9

Also went. 14 50 on sprockets with a new chain.

  • 2001426noob

Posted September 08, 2015 - 03:48 PM

#10

Bought a 2001 wr426 this spring and have been loving it ! Unfortunately Me and a buddy crashed long story" and I broke my wrist so im out for the rest of the season . When I bought the bike it ran awesome but lately it has developed a piston slap or some type of odd knocking pinging noise . Thought it was bad gas from the shitty gas station I had to use last riding session . It wasn't . Checked the valves and the exhaust valves are at 1.5 and the specs say they should be at 2.0 or 2.5 . Could this be my knocking piston type slap I'm herring . I ordered a shim kit but haven't but able to get it done because of this broken wrist ... Also if I wanted to rebuild the inside of my engine "even know it's running good" what would you suggest starting with parts wise

Edited by 2001426noob, September 08, 2015 - 03:55 PM.


  • 2001426noob

Posted September 08, 2015 - 03:57 PM

#11

ImageUploadedByThumper Talk1441756584.387165.jpg

ND plated as well

  • 2001426noob

Posted September 08, 2015 - 04:02 PM

#12

When I got my bike I did a custom dual sport conversion. Saved me a lot of money and looks better then a Baja or tusk lighting kitImageUploadedByThumper Talk1441756833.018648.jpg ImageUploadedByThumper Talk1441756879.039760.jpg ImageUploadedByThumper Talk1441756911.373169.jpg ImageUploadedByThumper Talk1441756944.894580.jpg

Edited by 2001426noob, September 08, 2015 - 04:02 PM.


  • nilknarf

Posted October 06, 2015 - 03:31 PM

#13

Okay- with this one I'll try to stop hogging this thread... (right!)

 

Finally started the old beast for the very fist time since I've owned it and rode it around for just a few

IMG_1335_sm.jpg

Even with the pea-shooter stuffed into the muffler, it feels like it has twice the wheelie power of the ol' xr600 in the background with only half the weight- now I can't wait to get it broken in! Still have a few cosmetic mods to go over (new plastics, maybe some graphics) and then it's time to see if I can get some plates too!

 

Curt

Update: Got my plates! Inaugural trail ride was a bust- trashed water pump seals and a completely clogged pilot jet cut my day short- I've since un-clogged the jet and replaced the water pump shaft, seals & gaskets, but haven't ridden it again yet as I've been re-wiring for all the required street gear... almost done!

 

Curt



  • nilknarf

Posted April 06, 2016 - 02:18 PM

#14

New update on my 426: Got all the lights, turn signals, horn, mirror, battery, rectifier-regulator (Tusk)... replaced my fuel screw, replaced the needle with an OBELN from a yz250f and leaned my main jet just a bit... this thing really woke up- yee-ha!

 

Curt







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