1987 Honda XL 250R restore / rebuild.

Discussion in 'Thumpers' started by RatchRacing, Jan 1, 2013.

  1. RatchRacing

    RatchRacing Adventurer

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    Hi ADVer's! I've been a lurker on the site for a while and feel that I've got something to contribute now. I've been riding dirtbikes for the last 10 years and have wanted a dual sport for a while to do some back country exploring on. A new bike is out of the budget right now, wife and kid comes first.

    I picked up a 1987 Honda XL250R for $500 from Kijiji for a cheap dual sport project. I've heard positive things about the reliability of these old machines and figured it would be a worthy project. Its a non-runner and needs some work to say the least.

    This is what she looked like when I got it home.


    I put a carb rebuild kit in it and got it running. Not very well though. I also noticed that the head gasket was covered in silicone :baldy

    So the bike and engine will come apart for inspection and refurbishment.
    #1
  2. RatchRacing

    RatchRacing Adventurer

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    Got the bike torn down and the engine out.

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    So far it looks like someone has done some engine work to the bike, not very well though. All the gaskets are silicone covered, loose bolts everywhere, valves way out of adjustment.

    More to come.....
    #2
  3. RatchRacing

    RatchRacing Adventurer

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    Tore into the engine to give it the once over. Found some good stuff and some bad inside the engine.


    Popped the jug off and found that the oil ring was broken, most likely by the stupid oaf that installed the piston backwards while putting it on.



    The cylinder wall has a scratch in it from the broken ring , I'm hoping it will just hone out since the clearances are all within specs. You can just barely feel it with your fingernail. Looks worse in the picture.



    Looks like since the piston was in backwards it had a run in with the exhaust valves. Damage to the piston will buff out. I'll have to check out the exhaust valves to see if they are bent though.



    KR6 is the code for the stock Honda piston but this one seems to be oversize by 0.50mm.



    The piston diameter measures out to 75.5mm, stock bore is 75.0mm Should be easy enough to get the oil ring from the Honda dealer. I just hope the scratch in the cylinder wall will hone out.

    I also found that the kickstart splines are NFG and the decomp was not setup right, no wonder it wouldn't start too well.
    #3
  4. valvecrusher

    valvecrusher tractus pro pensio™

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    :lurk


    nice...
    IN. where it should be EX.(piston reversed)


    you can see the '50' (.5 over)
    stamped in ink on the KR6 piston........


    hit me up if you have any questions, or need any wierd OEM parts...
    got a few of these, and currently they are non-op/non-titled



    Those exhaust valves are CERTAINLY bent, even if just the faces....so DO replace them..
    you can see where the ex. valves tapped the piston...

    That wouldn't have happened if the piston would have been turned the correct orientation..it has reliefs cut into the piston crown...
    #4
  5. TNC

    TNC Candyass Camper

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    I had 4 of those bikes from '84 through '90. They're really fun, tough bikes. I even raced long course, "B" class enduros on these, and it wasn't too much of a handicap. That looks like a fun project even if it is a little rough. It's clearly evidence that some people shouldn't be allowed to use tools for anything more critical than a sticky door hinge.:D
    #5
  6. Stretch67

    Stretch67 Mad Scientist

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    I've had mine since I bought it new when I was 20. :clap

    They are great little bikes. I broke a couple teeth off of the kick-starter gear a few years ago. Parts are still mostly available, no big deal in this case.

    Do be careful of the rubber intake boot. If it cracks due to careless handling, the bike just won't run right. I've occasionally seen New Old Stock replacements on eBay... for well over a hundred bucks.

    I've subscribed to this thread. Do keep the photos and commentary coming. :freaky
    #6
  7. Leo.G

    Leo.G Is still learning

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    Hey!

    Really nice project!
    I wish I could find bikes as cheap as that here in Argentina.. For that price, the best you can have is a 125cc 2stroke, such as a TS or a DT...

    Hope you can make a nice bike out of that one, and also hope the scratches on the cylinder walls to be gone with a hone, so as to change just the rings and keep the piston.. If not, you'll need to go to the next piston/ring size.. you could get a Wiseco or another good piston, it wouldn't be that bad..

    I'm suscribed and I'll keep an eye on this!
    Cheers from the south!
    #7
  8. RatchRacing

    RatchRacing Adventurer

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    I have a parts engine that came with the bike, exhaust valves look good in it so I might luck out. I'll PM you if I run into needing some used OEM parts. Thanks for the offer.

    I've read a few things about the intake boot cracking and have been very careful handling it. It looks to be in good condition but I'm not taking a chance with a 25+ year old bike.

    Thanks for the interest in my project guys!
    #8
  9. RatchRacing

    RatchRacing Adventurer

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    Got some work done on the XL tonight....

    Someone went full on dumb-ass with the flange sealant on brand new gaskets :huh



    Good head

    ]

    Donor head



    Removed the exhaust valves from the donor head in case I need them




    I started my inspection of the good head and the exhaust valves that are suspected to be bent. I did the contact cleaner test, filled the exhaust port with cleaner and checked for any fluid leaking past the valves. Everything checked out, so far so good.



    Removed the exhaust valves and checked them out. Honda spec for valve stem warpage is 0.002", they were less than that. I also put the dial indiactor on the valve face to make sure they were straight, they also checked out good (not pictured).

    MG]

    Comparison of the exhaust valves from the good head and the donor head. The ones from the donor head are NFG,



    I then turned my attention to the cylinder and the nasty looking gouge in it. I honed it out real good and checked the gouge, seems ok. You can still see the affected area but can just barely feel it with your fingernail. I might just leave it go. I took a few detailed pics and a pic with the piston ring in the cylinder to show that there is no gap at the questionable area.



    I checked out the cam and rockers. The cam has some marks on it but is smooth and well within specs. The rocker faces on the exhaust side have a groove worn into them quite badly. I first suspected oil starvation but given that everything else looks good I'm leaning towards whoever did the previous engine work also f*cked up on the exhaust valve adjustment (or lack thereof) and had them WAYYYY tight causing the wear :baldy

    http://i2



    ]

    I'll have to replace the exhaust rockers, clean up the valve and install new seals, get some piston rings and the top end is well on its way being put back together. I should also hit it with some paint so it looks pretty.
    #9
  10. Stretch67

    Stretch67 Mad Scientist

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    I hope it is just a previous owner keeping the valves too tight, and not a bad batch of rockers (which would most likely include mine as well). [​IMG]
    #10
  11. RatchRacing

    RatchRacing Adventurer

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    I'm sure it was the PO that f-ed up, the intake rockers are mint. Just both exhaust rockers are looking to be toast. I looked up OEM replacements on bikebandit and they are $48 each :eek1
    Maybe I'll take these ones to the machine shop near work to see if they can be repaired.
    #11
  12. RatchRacing

    RatchRacing Adventurer

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    More work done this morning on the XL, mostly little piddly stuff now. I'm waiting for parts to come and and I need to clean and paint alot of stuff. Might have to take a trip to Princess Auto to buy a parts wash tank, would be alot easier than carting one part at a time to work for cleaning. Anyways.........

    Stripped the rear suspension and electrical off the frame.
    [​IMG]

    Removed the linkage from the swing arm, I'll also be cutting off the mounts for the useless chain guard to save some weight and not look so ugly.

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    Went after the rear fender next. The fender has a heavy steel brace to support the weight of the tail light and licence plate bracket. I'll be removing all this for something a little lighter and more compact if I can rig it up.

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    The seat needs recovering badly. I tore it down to the pan, foam is in good shape but I'm toying with the though of adding an extra thin layer of foam to make a bit of a "tall" seat.

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    Airbox needs cleaning and a new filter element

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    The tires on the bike are brand new, BUT, the rear tire is a 5.10" tire, stock spec is 4.50". This tire barely fits but should be ok since I'm ditching the chain guard. The front is a knobby Trackmaster tire that will not suit the type of riding I plan on doing with the bike. I'll swap it out for a new K270 front to match the rear already on the bike.

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    Decided that I'd clean up some of the factory defects in the intake and exhaust ports

    [​IMG]

    Hopefully some parts start showing up so I can button the engine back together .
    #12
  13. RatchRacing

    RatchRacing Adventurer

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    Another thing.... does anyone know what parts are inter-changeable with the XR250R of the same year? I'm wondering if and XR tank would fit the XL. I could lighten the bike up and bit and increase fuel capacity if so.:evil
    #13
  14. Stretch67

    Stretch67 Mad Scientist

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    Dang. You're seriously inspiring me to restore mine. Back a few years ago when it was my only trail bike, I painted it blue to keep it from being so conspicuous as I trespassed on some other guy's land.

    I never did like the '87 XL250R color scheme, so it didn't pain me to change the color. But now that I have a couple other dedicated trail bikes (and ride legally), I believe I'll get my XL gussied up again, perhaps red like an '84 model.

    Hmmmmm... :evil
    #14
  15. RatchRacing

    RatchRacing Adventurer

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    Glad I'm inspiring someone to work on an old bike. I love doing it and this is not the first one I've done :evil

    Got more work done today.

    Gave the frame a nice cleaning
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    Cleaned up the swingarm. Cut off the clip mount for the chain guard since I won't be using it. Also cut off the protruding mounts for the passenger pegs. A nice coat of paint made it look cherry.
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    Grease up the pivot shaft..... I was lucky enough that the previous owner put new needle bearings in the swingarm pivot!
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    Installing the swingarm and suspension linkage

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    Greasing up the shock bushings

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    Rear suspension is all back together!

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    Gave the wiring a quick wipe down and installed.

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    Began cleaning the clamps assembly

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    Quick clean of the airbox and put it back together. Also removed the flashback screen.

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    Gasket kit came in the mail today!!!!

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    Lots more to come yet........
    #15
  16. redprimo

    redprimo Been here awhile

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    your doing a lot of work and its looking good. I wouldn't use that cylinder with that big gouge in it like that. I know you said you can barely feel it with your fnger nail but, it looks like it is a couple of thousandths deep and that is too much for my taste.

    I know the delima about not wanting to buy a new piston. The slug in my xl500 had a bit of a scuff mark and I really wanted to just put new rings in it and put it back together. It was just a tad more than I was comfortable overlooking and now I'm glad I popped for a new piston and a bore job. The way the rest of my restoration job is coming along I am now glad I will have a 100% top end to math the rest of the bike.

    Don't forget to check your valve spring lengths.
    #16
  17. RatchRacing

    RatchRacing Adventurer

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    I did some "agressive" honing to the cylinder and the gouge is all but gone. I measured it at work with a micrometer and there is no difference in bore diameter where the scratch was. You can still see where it was but can no longer feel it. I'm comfortable running it at this point as it measures within spec.

    Sent from my GT-S7560M using Tapatalk 2
    #17
  18. RatchRacing

    RatchRacing Adventurer

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    Got the top clamp and the dash installed. Things are going a bit slower now that I'm waiting for parts.

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    [​IMG]


    Sent from my GT-S7560M using Tapatalk 2
    #18
  19. G19Tony

    G19Tony Been here awhile

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    Nice work. I love seeing an old bike brought back. :clap
    #19
  20. heart_of_darkness

    heart_of_darkness Adventurer

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    Looking at the wear pattern in the exhaust valve, it looks to be skewed slightly. I also got a used XL250 with a backwards piston, and also thought the valves were okay despite indentations on the piston, until I chucked the valves in a lathe and immediately saw the bent-ness.
    #20