Yamaha WR400F

Discussion in 'Thumpers' started by a1fa, Jun 5, 2009.

  1. BIG ED XT FAN

    BIG ED XT FAN Long timer

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    Have some great Yamaha WR 400F FUN!!!!:rofl:lol3:eek1
  2. dvgonzo

    dvgonzo Been here awhile

    Joined:
    Dec 26, 2004
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    Location:
    Albuquerque, New Mexico
    Well I decided to off load the 400. Hate to but have just decided the constant kick starting when clearing trail is just not the hot ticket due to the new parts I had installed on me! (New aftermarket knee!)

    Fortunatley I have a later model one ('03) that came with a button!

    I ran an ad here locally and got no response...yet...probably cause it is mid winter and I priced it pretty high due to all the extra's I have for it.

    I am now thinking I should start to off load some of the extra's and discount the price accordingly as they sell.

    Here is the link to the ad, really pimped out and so much extra stuff for it! No pics as camera is dead. If interested in any of the parts let me know.

    http://albuquerque.craigslist.org/mcy/2785551865.html
  3. RandoCommando

    RandoCommando Wannabe

    Joined:
    Oct 12, 2011
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    Location:
    Philthadelphia, Pennsylvania
    Ok. So I found a bike near me that is for sale as stated in the title.
    A few questions.
    Has anyone had any problems converting this to a street legal dual purpose?
    What kit did you use?
    Is the seat height 39"?
    Can it be lowered for cheap? If so,with what lowering links?
    I found lowering links that were like $150. YIKES!
    I've also read conflicting specs on this.
    What is the actual wet weight and horsepower?
    Lastly. Is $1500 a good price for a one owner bike that was well maintained?
    I have a KLR 650 that I currently ride the streets and trails, but it's a top heavy beast with low power.
    I'm thinking the WR400 might be a good alternative for the dirt and trails.
    Any and all help/advice is appreciated as I'm looking to buy this week.
    Thanks!
  4. marbee40

    marbee40 Some Fear is Good

    Joined:
    Jan 28, 2007
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    Location:
    45 minutes-North-of-Los Anchorage
    2001 WR426, no mods.

    Bought this year. Ran like a champ after cleaning carb. I'm the 2nd owner.

    Two weeks ago, bike stalled, no compression. Pulled apart. Found two pieces of the little cam shim laying down below the rotor (flywheel?). Didn't know what the metal was, but it definitely broke the cam chain. Popped the covers off the cam and found one shim correctly in place above each cam. Original owner (or mech) must have dropped one at some point and neglected to go after it. :-(

    Pulled head and cylinder. Piston and valves look to be in excellent condition. Did NOT pull valves, just looked at all five plus piston. Didn't appear to be any damage.

    Put on new cam chain, set piston TDC, put cams on correctly per the manual. Put it all back together. When kicking I get no compression...ie when kicking, the kicker doesn't come to a stop, requiring the use of the compression lever on the bar. Used to start 1st time, every time.

    Ideas? Is it possible the previous owner had the YZ timing (rotated exhaust cam one tooth clockwise) and now it won't start cuz I have is set to WR stock? Maybe a bent valve that I can't see unless I pull them out?

    THanks,
    Jim in AK
  5. a1fa

    a1fa Throttle Jockey™

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    Sounds like you are not timed right. Verify to make sure you don't have WR450 cam. If you do, you need to off-set the timing a bit.

    Still have the manual decompression lever?
  6. dvgonzo

    dvgonzo Been here awhile

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    Bummer!

    Are you sure it was one of the cam chain adjustment shims? Did you find it all? Or enough to tell for certain that is what it was?

    Reason I ask is just to be sure it is not a flywheel woodruff key as that could also break the chain and would look sort of the same after getting chewed up by the chain/sprocket. Would also keep timing chain from turning and piston/valves from cycling up and down. I imagine you would have noticed that though....just a thought.

    A few weeks back two buddies were doing a KTM and dropped a shim, they looked for several hours, used magnets, wire , mirrors, and finally gave up. I got lucky and found it within a couple minutes of starting to look for it and can see where some folks would get tired, button it up and later it breaks.

    Could you tell if it got caught up high in the cam area (marks on the cam sprockets, caps, etc?) or down behind the flywheel or in the chain tensioner area? It should have left a few marks and maybe some other damage if when it got caught and stopped the motor.

    Sometimes the sudden stop will shear off that same flywheel woodruff key I mentioned earlier, or weaken it enough it will finish breaking if re-used.

    Keep us posted.
  7. marbee40

    marbee40 Some Fear is Good

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    I just tried to upload the pic of the cam shim and the broken piece but tapatalk giving fits. Anyways, thats what it was. We had pulled the flywheel to install new chain and woodruff on crank is fine.
  8. dvgonzo

    dvgonzo Been here awhile

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    I would then try to see where the shim got caught like I mentioned, up high or down low and see if it might have mushed out some other metal or a sprocket tooth that might be stopping or catching the chain.

    Depending on what it stopped first (cam, chain,) and where it stopped it up, (Shim against a bucket, or cam cap, etc.), will determine what else got trashed out.
  9. marbee40

    marbee40 Some Fear is Good

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    Oooh.... Good points. My "ass-ump-shun" was it hopped up off the bottom of the case and wedged in btween the crank gear and cam chain. Ill look for tweaked teeth, etc.
  10. marbee40

    marbee40 Some Fear is Good

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    Both outside intake valves tweaked. Ordering tinight.
  11. dvgonzo

    dvgonzo Been here awhile

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    I would imagine since it is two they may have contacted the piston.

    I see where you said the piston looked good but can you see any faint marks or gouges on the piston or valves to verify that is what caused it?

    Valves can get bent pretty easily when a piston contacts them so
    hopefully was not to hard a hit so nothing else got wankered.
  12. marbee40

    marbee40 Some Fear is Good

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    I finally got the durn thing running with the help of AKMud and Friar. Long story short, one silly little dropped cam-clip required a new cam chain, two new titanium (UNOBTANIUM) valves, two shims, and a woodruff key on the crank to get her going again!

    Thanks all!

    Jim
  13. Kawidad

    Kawidad Long timer

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    Too late now, but Ti valves are not a good idea. Check them often. :deal
  14. MingRidesBikes

    MingRidesBikes Been here awhile

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    Hey guys had some questions for ya about the wr426f. I recently purchased an 01 wr426f. looking to get the most power out of this bike. I had a 05 wr450f deristricted that was an absolute blast to ride. With that said I like my new to me 426 a lot. Smooth shifting, linear power band, but would like some more umph. it currently has a yz426 pipe on it. what mods will really bring it alive? I was thinking over the winter to do a yz450 exhaust cam, was contemplating getting a yz426 aftermarket pipe (i.e. fmf or a t-4) not sure how much more power that would be than the current yz pipe on the bike. Anything else to help bring this bike to life? And honestly will it ever have the power the 450 had? Thanks for your input guys.
  15. Kawidad

    Kawidad Long timer

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    Not really a power expert, but the cams will help. However, the supposed gain is in ease of starting, not really a power mod. Another mod you can do is switch the carb to a 450 carb. Again, it is supposed, the internals of the carb are better engineered since it's newer so that allows the bike to run better. I did it on my WR400 and it worked pretty well, but more power, who knows.

    Honestly, though, only by dumping big $$ into it will you get any reasonable performance gains out it. Otherwise, it's only going to be modest gains, if at all. :deal
  16. LucasLeader

    LucasLeader Been here awhile

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    Make sure this is done first: http://www.thumperfaq.com/throttle.htm The WRs can only open to 3/4 throttle from the factory. That site is for 250s but still applies to your bike. Check out the other free mods on there and do all of those. Also get your jetting squared away and if you have a bad bog look into messing with your accelerator pump. I've heard people say the 426s can be just as fast with the 450s with the basic mods.
  17. yamahaman

    yamahaman wannabe bike builder

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    Location:
    melbourne Australia
    I have got a Hybrid yz/wr motor and I have tried everything with some good sucess and some bad! From personal experience the 450 cam is Not Quite right. If you can afford it, the hotcams (no affiliation) cams specifically for the 426 in the yz is really good http://www.hotcamsinc.com/ProductInfo.aspx?item_id=566
    more power, easy starting and no stalling when brake sliding due to the auto decomp

    The bk mod
    http://motoman393.thumpertalk.com/tech/carbpics.html
    http://motoman393.thumpertalk.com/tech/carbinfo.html

    Make sure you have this matching carb with the red hot start button

    The last option is the Vortex ignition I am friends with the owner of vortex and he has given me one of these that is tuned for the wr lighting coil/stator and it has a max power tune and a max tourque setting awesome http://www.vortexcdi.com/model_product.php?product=1&model=33&mp_id=1336

    These three mods will give you all you need to give the bike all you can without loosing reliability


    I have had Standard yz pipe, Titanium DSP pipe, FMF and also currently running a CRD pipe the power is un-noticable between all of the aftermarket pipes, just keep the yz its neat, works ok and not overly loud.

    I also have mixed the yz and wr grearboxes to make a custom box 1st wr 2nd yz 3rd yz 4th yz & 5th wr (this was popular with the european enduro guys when the bike came out)

    I have run the wr box and yz box, I have found the yz to last the longest and be the most useable in the woods where as the wr box is a bit better for the open stuff. Be aware these bikes are suseptable to fifth gear not holding due to loading up the gear and not reving it out dont labour the bike in fifth keep it on the boil and the gearbox will last

    I have done heaps of work on these motors and have come accross all of the major problems that can be encountered with them, great bikes if you know there limitations and more help pm me

    :1drink:1drink:1drink
  18. MingRidesBikes

    MingRidesBikes Been here awhile

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    Thanks for all the info! I'm gonna be reading into the carb and ignition mods. Didn't think these would be substantial area's of opportunity. I do need to check the throttle stop screw for sure. I know it has the yz pipe I believe off an 2001? they are different between 01 and 02 if I'm not mistaken. And when doing the hotcams from the 426f, The exhaust is for auto decomp, the intake is where the power comes from correct? Jetting I'll have my shop dial down, is there an airbox mod that actually helps this bike breathe and get more power, or keep it stock?
  19. ADV-Wes

    ADV-Wes I'm not lost....yet.

    Joined:
    Aug 2, 2008
    Oddometer:
    176
    Location:
    NE Victoria (Aus).
    Anyone direct me to where I can download a Workshop Manual for 1999 WR 400F??

    (And in the meantime, does anyone now the oil volumes for this model? A mate who knows even less than me about bikes has left one a my place for me to clean up for him!:huh Oil change, new clutch, Clutch cable, de-comp cable, clutch perch, brake pads.......the list goes on...........my latest project :lol3)

    Cheers,
    Wes.
  20. yamahaman

    yamahaman wannabe bike builder

    Joined:
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    Oddometer:
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    Location:
    melbourne Australia
    The specs are the same for 426 400
    1.5 litres of oil with out filter change
    1.6 litres of oil with filter change
    1.7 litres of oil total (there is always 100ml of oil left in the bike after and oil change)

    inlet clearances of 0.10mm - 0.15mm cold
    exhaust clearance of 0.20mm- 0.25mm cold

    drive chain slack 40mm - 50mm (measured at last bolt on top of chain slider between slider and chain)

    that should get you started message me for more info

    :1drink:1drink:1drink