Brtp4's XR250R Build

Discussion in 'Thumpers' started by Brtp4, Mar 7, 2011.

  1. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    Back in January of 2010, we had a break in the weather and I went on a ride with some local friends. I was riding my XR650L, which is now fairly modded. It's old, but competent. On this ride, it was warm, and a mix of mud, melting snow, and maybe a little ice. Trails were not that technical, but greasy. Looked like this:

    [​IMG]

    After getting worked with the weight of my heavy XR650L, it was painfully clear I needed a lighter bike for singletrack riding. I do not really have the youthful sharp reactions to ride a 2T well any more, so I was thinking about a small to mid sized 4T bike, that could be plated. Being a project kind of guy, I also wanted something that I could build from the ground-up. Once done, I would ride it for a while and eventually keep as a spare.

    My shortlist had several models, ad I was hoping for something hammered or blown up so I could get it cheap. A person I knew mentioned "I know of a blown up XR250R, a newer one.". It was not the first bike on my list, but I called the seller, The bike was in good condition, but did not run. He wanted to cut a deal over the phone, explained that it seemed like it broke the cam or something. He wanted $850, I told him that if I had to commit sight unseen, I would go to $650. He agreed. Hopped in the truck and drove down from Bend to get it.

    It was a bit neglected but had very little use:

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    More.

    BP
    #1
  2. motowest

    motowest Two-wheeled Adventurer

    Joined:
    Feb 28, 2005
    Oddometer:
    1,369
    Location:
    Santa Cruz, CA
    It's nice when things work in your favor. Much better than hearing an unexpected list of parts that are needed ($$$$).:D
    #2
  3. Garthe

    Garthe ROCKS ARE YOUR FRIENDS...

    Joined:
    Nov 27, 2004
    Oddometer:
    4,357
    Location:
    Arizona
    :clap


    :bert
    #3
  4. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    I power washed it on the way home, cleaned up really well:

    [​IMG]

    First thing I did was drop it off at my friend Matt Worbes shop, M-Tech Motorcycles to diagnose. After a day he calls me. BTW, Matt is a man of very few words.

    "Your bike is ready."

    "What do you mean "ready"?"

    "I mean it's running."

    "Huh?"

    "Yea, running. Pilot jet fell out. Put it back in and it fired right up."

    $650 for a running 2003 on the original tires. I was pretty happy.

    More...
    #4
  5. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    Back when I was talking to the PO, I asked him to check one thing on the bike for me. The swingarm pivot bolt. On XR250s and 400s, because the pivot blot passes through the motor, it cooks out the grease, the bushings freeze on the bolt, and make it difficult or impossible to remove. It is the achilles heel of these bikes.

    I really did not think I would have an issue, since it was fairly new. I was kinda wrong:

    [​IMG]

    I squirted things up, waited a day, and started by tapping on the nut with a plastic hammer, then a ball peen, then a mini sledge. Holy smokes, it would not budge. I then took an old extension and started wailing on it. STILL nothing. So I tipped it 45 degrees, lubed the heck outta it, and went at it the next day. This time I had my wife turn the other side with a ratchet while I pounded. It finally came out:

    [​IMG]

    Pretty surprising how dry and rusty it is, for a bike in that condition. Even left a pile of dust on the floor:

    [​IMG]

    After a lot of wire wheeling. Bolt was fairly pitted:

    [​IMG]

    (sorry, cell phone pic)

    [​IMG]

    Just to be sure, I replaced the bolt and bushing because of the pitting. I probably could have reused them, but bought a new OE bolt ($65....f me.....) from Honda along with new bushings. I saved the old one, just in case. Bearings were fine, only the bushing-to-bolt interface was fouled. Greased everything back up and put the bolt in.

    Afterward, the extension became too mushroomed to fit into a socket.

    More....

    BP
    #5
  6. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    The first thing was to fix the awful playbike riding position. Honda mounts the bars quite rearward, and gives them a lot of sweep, putting the rider back and making it really hard t weight the front wheel.

    [​IMG]

    [​IMG]

    Added some CR Mid bars, good height with little sweep. I also got a new Billet Racing Products upper triple, that places the bars much more forward:

    [​IMG]

    The clamps move things about 1.25" forward, and the bars place your hands another 4.5" fwd:

    [​IMG]

    When I pulled the triple off, things were dirty:

    [​IMG]

    That is not rust on the star nut, it is this Norcal clay. I pulled everything apart, greased all the bearings, and put the controls back on:

    [​IMG]

    [​IMG]

    [​IMG]

    I skipped the handguards at the time, will add them later.
    #6
  7. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    While I was researching the little XR, a friend told me about an article in an old DIRT BIKE magazine. The January 1999 issue had a comparison test of 4 XRs done at Scott Summers ranch. Summers and 6 other riders compared a stock XR250R, stock XR400R, a modified XR280R, and a modded XR440R at his ranch, a 4.5 mile loop, riders with mixed experience. Reprint of their lap times:

    Name..............XR250R.........XR280R.......XR400R........XR440R
    Summers.........9:42.43........9:14.02.......9:17.81.......9:22.95
    C.Smith..........10:08.98......10:07.03.....10:09.22......10:20.75
    Larocco..........10:40.84.......9:48.50......10:03.62......9:55:17
    Ziegfelder.......11:42.69.......10:59.28.....11:17.97......11:14.27
    Michaels.........10:53.42.......10:43.28......10:44.34......10:43.18
    Parlin.............10:18.00.......10:08.16......10:06.27.......9:59.67
    Jones.............13:39.30.......12:55.84.....12:54.56......12:57.58

    This does not suggest that the XR250R is as fast as a modern bike, but if set up right, it would work for me. I figure the 250 kept up for a few reasons, first, because it is smaller, lower, and has a wheelbase 3" shorter than a CRF250/450, a big difference. Also, because it has less power, it was easier to ride, which would be good for me.
    #7
  8. hanksmybuddy

    hanksmybuddy Been here awhile

    Joined:
    Jun 17, 2009
    Oddometer:
    412
    Location:
    Tacoma, Washington
    Excuse me sir but do you think I could get a written report mailed to me on this in the form of a book report. I'm very interested in the epifany thing you talked about in one of your earlier posts. To be honest with you that thing looks like a rat trap. I'd part it out before you have another epifany or something. :wings
    #8
  9. Dakar Dan

    Dakar Dan Long timer

    Joined:
    Feb 4, 2007
    Oddometer:
    1,061
    Location:
    Bendigonia
    Hey, is that an old skool Stumpjumper there?
    #9
  10. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    One of the very last steel frames. Got it as a frame only. Built with XTR and a Judy, now I have it set up for wifey.

    BP
    #10
  11. HighwayChile

    HighwayChile greetings from Wa state

    Joined:
    Aug 19, 2003
    Oddometer:
    4,710
    Location:
    Bow, WA USA
    come on keep postin' :1drink
    I agree with the less being more, I"m a slacker when it comes to riding and although big HP is fun in the right area its a hand full in others. I started on a '65 honda trail 55 ( thats an early Advbike, probably where BMW got the GS idea ) 43 years ago, I'll probably end up on a 50 ( hot rod Derbi, maybe) if I make it long enough.
    the rougher it is the more fun you will have, the fast sections well that when to bring big red.

    thought of a new front end, USD? rear shock swap?
    #11
  12. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    Siince I was in there for the swingarm bolt, I figured I would do some maintenance and re-springing on the rear suspension. I pulled the rear linkage and the shock off the bike:

    [​IMG]

    [​IMG]

    It is always important to spring the rear for your weight. I got an 12.0 spring from Eibach:

    [​IMG]

    ....and found Les from LT Racing (www.lt-racing.com), who has a couple XRs, one that is really trick and one that is absurdly so. He has links to them on his website, click here. Several people recommended him so I sent the shock to him to revalve for my weight.

    [​IMG]

    Cleaned up a bit, and of course always, always, always pack things up with grease:

    [​IMG]

    Swingarm back on:

    [​IMG]

    And suspension linkage:

    [​IMG]
    #12
  13. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    XR250s are playbikes, not race bikes. But the designhas good characteristics: short wheelbase, 6 speeds with fairly close spacing, a Honda, and a mild state of tune that responds well to mods. A CRF250 has considerably more power, but some folks have raced the little 250 with good success. Here is a horsepower graph of the two:

    [​IMG]

    More.....

    BP
    #13
  14. n16ht5

    n16ht5 ride the night

    Joined:
    May 6, 2010
    Oddometer:
    2,545
    Location:
    Arlington, WA
    wow, looks like a great build! Going to be one nice bike.

    I have an 01 XR250R, wouldn't trade it for anything. Definitely subscribing to your thread. I never knew about those triples, going to look into that. How do you like the FMF ..Q4?

    My bike doesn't have much for engine mods... mostly everything else. when it needs a teardown I'll open it up to 300CC

    [​IMG]
    #14
  15. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    That bike is nice, the ride looks even better.

    The Q4 is really nice. I have a PC pipe on my other bike, the FMF is quieter.

    BP
    #15
  16. HighwayChile

    HighwayChile greetings from Wa state

    Joined:
    Aug 19, 2003
    Oddometer:
    4,710
    Location:
    Bow, WA USA
    interesting on the dyno specs, you should be close after some mods, with far better reliability - esp in the valve train area.
    what you are describing above in riding style is what under powered 4 stroke riders subscribe to, works well
    Great thread :1drink
    #16
  17. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    I picked out some M12 XC tires based on a recommendation from a friend. I got a 130/80x18 rear, and it is a little smaller than other tires with the same numerical size. Seems perfect for this, not too much tire.

    On thing I did was to put both tires in with Bib Mousse, as I hate changing tires. I will not be doing extended slab on this, so they should hold up well.

    On gearing, in the case of the little XR, some people say that you should gear them up. Stock gearing is 13/48, or 3.69. I looked at some application charts, and decided to go with a 13/45 (3.46) set from Supersprox:

    [​IMG]

    Everything gets blue Loctitite, especially sprocket bolts:

    [​IMG]

    Sprocket w/XRs Only Guard:

    [​IMG]

    Once I added the XRs only guard, the stock cover would no longer fit. But I did some Dremeling on it:

    [​IMG]

    cleaned it up with a wire wheel:

    [​IMG]

    And got it to fit. I now have a stronger case protector, and it looks like stock:

    More....

    BP
    #17
  18. YamWOW!

    YamWOW! Been here awhile

    Joined:
    Oct 25, 2008
    Oddometer:
    460
    Location:
    Kennewick Washington
    :lurk
    #18
  19. TourPros

    TourPros Local wherever I go

    Joined:
    Dec 20, 2008
    Oddometer:
    2,045
    Location:
    Hood River, OR
    Brian if you do a search for ENGINE CASE SAVER GUARD PLATE HONDA on eSlay you will find what you need for your shifter protection on the case.

    Looks like it will be a fun little bike. I would be a little scared on something like that LOL. My fat ass would get to comfy in the idea that I could throw it around :evil

    Looking forward to following the build
    #19
  20. Brtp4

    Brtp4 Powdercoat it.

    Joined:
    Sep 23, 2006
    Oddometer:
    1,983
    Location:
    Bend, OR
    The first step toward getting these to breath is to grind the awful OE Honda exhaust flange welds. Honda welds up the pipe to the flanges unbelievably sloppy, so that the pipe is restricted 20% or more of its diameter. Take a look:

    [​IMG]

    That is not carbon buildup, it is the weld itself. Some time with the Dremel and you can see the difference on the left side of the flange.

    [​IMG]

    Added an FMF Q4:

    [​IMG]

    Workmanship is great and the bike sounds good and is not loud.

    More....

    BP
    #20