NX250 Thread -- official ADV owners manual

Discussion in 'Thumpers' started by valvecrusher, Mar 17, 2008.

  1. travial

    travial Adventurer

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    @spychic I've been riding on the Duro median HF903?4 tire for about 7 months now, I think the best compensation for the larger circumference is to go up two teeth in the rear sprocket. I went up one tooth but I feel like two tooth would better hit the powerband at highway speeds, and also provide more low-end grunt in first and 2nd gear.

    And the Doro definitely raises the back end a bit, but you can compensate by adding a 3/4 to 1" PVC spacer into the top of the fork tubes (search the NX250 posts for more instruction there), or I bought some CRF230L front fork Springs and cut them down to about 1" inch longer than stock Springs (also see other NX250 posts on the subject). Either option will raise the front end a bit to compensate, not to mention that the stock fork's notoriously soft so it's probably a good idea anyway.

    @arescec You might also want to check and make sure none of the little o-rings fell out of the carb when you were cleaning it last. I about lost a tiny o-ring on the idle mixture screw which shot out while I was blowing out the carb orifaces with compressed air.
  2. arescec

    arescec Been here awhile

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    Swapped the CDI and seems the issue is gone. Have not fully tested it yet because it would start happening after, say, half an hour of open road.
    travial likes this.
  3. Too Old for This

    Too Old for This Adventurer

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    20190613_174049.jpg 20190608_222832.jpg

    Attached Files:

  4. kevNX

    kevNX n00b

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    Nice! Glad to see it’s possible.

    I’m almost ready to start on my project. I’m living in a fixer upper and I just replaced the old non-working garage/NX250 shop lights with LEDs.... which illuminated the oil stain under my bike :(
  5. Zic00

    Zic00 n00b

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    hey guys! little up date on the bike. just purchased all the parts I need to rebuild the carb. right now the main objective is to have it run. after that there might be an issue with the started switch but we shall diagnose that once its running in general. thanks for the replies I got/ hospitality, I was worried I was going to have to go on this adventure on my own because of the "obscurity" and age of the bike. super excited for this project.

    @PTC what are you asking for price wise? im kinda digging the look of that tank.
  6. arescec

    arescec Been here awhile

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    There are actually karb rebuild kits for about 20ish dollars specifically for nx250. Mine worked fine.
  7. Too Old for This

    Too Old for This Adventurer

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  8. Zic00

    Zic00 n00b

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    do you have a link to that? I couldn't find it when I was looking.
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  9. CORNATO

    CORNATO n00b

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    Hey everyone! I just bought a 1989 NX250 last weekend and have been wrenching on it and having a blast riding it. Runs just fine, but was missing mirrors and the previous owner had plasti-dipped all the body plastics. So I cleaned and polished everything, changed oil, and coolant. Put some mirrors and gas and took off! I ride a 2010 Honda Elite 110cc to class most days, but this bike is great for the interstate and longer rides.

    I've never ridden off road before and really love the idea of an adventure bike. I have lots of mods and upgrades planned. I generally like to keep my vehicles mechanically stock, but modify the body and etc. For this bike I'd like to: put a skid plate on, put crash bars/engine protector, add aux headlights, change headlight to LED(to free up wattage), add usb charger, add windshield, make pannier rack and removable top case, add hand-guards, and maybe a bigger rear wheel.

    So I'll start by showing some pics of the bike now!
    IMG_5883.JPG IMG_5882.JPG

    And I like to contribute so here's one of the first mods I've done to it!

    After cleaning all the plastics the bike was a bit...slippery. So I wanted to add some non-slip grippy pad things. But didn't feel like trying to find some that will fit and pay $30.

    So while at Harbor Freight, I was looking for the stuff you put in kitchen cabinets to prevent cups from sliding around, but non were non-stick. But I did find these non-slip tread pads that are supposed to go on stairs I think.
    IMG_5879.JPG

    So I picked one up for $3! Thought who cares if it doesn't work its 3 bucks.

    So I made a cardboard template by tracing the pad. Then cut the template to be half the size of the pad (because you need 2 and would hate to have one perfect and find you used too much material and have to drive back to HF).

    IMG_5880.JPG

    Checked the fit, looks good. Checked position with me on the bike, it's right where my knees hit.

    IMG_5881.JPG

    So now you cut out the pad material, don't forget to reverse the template. Remember you need 2 mirror image pieces, not 2 identical pieces.

    IMG_5884.JPG

    Now wipe the mounting area with alcohol to promote adhesion. And go ahead and stick them on. You can be like me and warm up both the pad and mounting surface with a heat gun to make sure it molds well, or just slap them on. Up to you. I also always hold anything I'm sticking on for at least 10 seconds with pretty good pressure.

    Anyway that's it! Looks good I think!

    IMG_5885.JPG

    IMG_5886.JPG

    Attached Files:

    travial, valvecrusher and Spurlock like this.
  10. Spurlock

    Spurlock Long timer

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    Hey Cornato, congrats on your bike, it looks to be in great shape! And nice job on the knee grips, I always liked how most pre-1970s bikes had rubber knee grips on the tanks, wish they had not gone out of style.

    -Bill
    CORNATO likes this.
  11. CORNATO

    CORNATO n00b

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    Hey everyone,

    I've been riding around and loving my Nixie, but have noticed a few things.

    I checked my front brake fluid and noticed it was pretty brown so went ahead and flushed and changed it. But now I noticed I can't quite get full pressure. It's not something I payed attention to before so it may have been a problem before or it may be normal. I can squeeze the brake all the way til it hits the throttle and feel like it has more to go. I worry that in an emergency situation I may not be able to brake adequately. Is this normal or is there something wrong? I have bled the brakes multiple times, I filled the reservoir to the point of overflowing to allow for some loss thru the bleeding process and still notice sponginess. Any advice is appreciated.

    I also notice around low rpms it sounds like the chain is slapping around. I have a manual and did the chain adjustment check and everything is in specs. So I'm just wondering if this is normal.

    And I have little tip, while first disassembling the body panels I snapped both of the mounting tabs off of the fairing. I just fixed it yesterday, let me tell you how. After doing a lot of research on the best method I instead used what I had around the shop. Cleaned the mating surfaces well, heated them up with a heat gun. Used super glue to glue the tabs in position. Then after that was dry I used JB Weld to reinforce the joint. I know this isn't the best method, but using superglue at first was a big help. Eventually I'll get that ABS plastic repair stuff or maybe a plastic welder from Harbor Freight.

    Also I just got a RAM mount after lots of recommendations and it great! I've used them before in my FJ Cruiser to mount an iPad and love the brand. But I'm blown away by the grip this thing has, I was very nervous at first. But 100 miles in and speeds up to 80mph on these sh#tty Louisiana roads and it supper secure. It shakes less than my gauge cluster, lol!
  12. Spurlock

    Spurlock Long timer

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    That spongy brake lever is definitely not normal, there has to be air in the system. A couple of things to try- first remove the bleeder screw and wrap with teflon tape so air cannot leak past the threads when bleeding. A Mighty Vac from auto parts store makes bleeding easier in my experience, but manually bleeding also works fine. Once done bleeding, with the bike on the side stand (so horizontal sections of brake line sit at an angle) wire the brake lever to the grip so it is pulled back about 1/2" and let it sit for several hours or overnight to let small bubbles migrate to the top. Then undo the wire and pump the lever several times using only the outer 1/2" of travel. You will likely see small bubbles coming up in the fluid.

    On the chain noise, do you mean the drive chain or cam chain? If the drive chain maybe the chain slider is missing from the swing arm? (part # 14 below)

    [​IMG]
    valvecrusher likes this.
  13. valvecrusher

    valvecrusher tractus pro pensio™

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    or there is a clog in the master cylinder, near the piston in the reservoir,
    allowing a squirt of brake fluid to actuate the pad, but not enough to fully pressurize the entire brake line...

    Not as common as an air leak, fluid bleed, water in the line, or a failed (collapsing/over-expanding rubber) line,
    but it is a plausible explanation for spongy brakes

    and the simplest explanation is usually the answer, I'm agreeing with you Spurlock, residual air in the line.....water in the fluid will also make the pad drag on the rotor..
  14. Zic00

    Zic00 n00b

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    Does anyone know of the size of the exhaust? The previous owner had it without a muffler so I'm trying to find an after market option. Or even links/ pictures to what you guys are using would be cool too
  15. Too Old for This

    Too Old for This Adventurer

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    I could not get all the air out doing manual bleed. Used Mighty Vac and worked great.
  16. helloish12321

    helloish12321 n00b

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    Oct 20, 2019
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    Charleston, SC
    Hi everyone.

    I just got home today with my first bike. Its a 1988 NX250.
    I wanted something simple and small with some power, preferably a honda. I checked craigslist this morning and there it was. I had thought about a dual sport for a while, and I thought it looked pretty sweet. I did a bit of research about it and thought it would be perfect. I already liked it a lot. Plus it was cheap and roadworthy.

    The previous owner and the odometer claim it has only 9000 miles on it. After getting home I dont quite believe them:nah. She's a bit rough at the moment!!
    Of course none of the plastic is held together correctly or in one piece, but its there!
    nx250 pic.jpg
    I've been looking online for information on these bikes besides basic articles and cant find much. I was reading the first pages of this thread from 08 and I'm surprised its still going. Anyway, I figured I would introduce myself, and maybe document some of the process of getting it cleaned up if anyone is interested.

    First thing is to get a plate on it. And take all the wood screws out of the fairing:thumb
    valvecrusher, CORNATO and PTC like this.
  17. Too Old for This

    Too Old for This Adventurer

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    Don't feel too bad. I bought mine with basically no fairings and tie wraps holding the gauge cluster on.
    At least you have something to work with.
    The bike looks pretty good in the pictures.
    CORNATO likes this.
  18. helloish12321

    helloish12321 n00b

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    I have some interesting news about my recent purchase :(:
    On the way home yesterday it misfired a lot in high gears at around 5k rpm. It also lost power and stalled once. I thought it might be a gunky carb or something.
    After researching I realized it was likely the CDI. I ordered a rick's hot shot CDI just so I know it will run right.
    Tonight I was in the garage stripping it down. I wanted to see about repainting parts, cleaning the carb, and checking out the CDI. I got the tank off and something wasn't right.
    IMG_0341.JPG
    Theres no CDI in here. And whats with these green wires?
    IMG_0342.JPG
    following the green wires I found it. Jammed under the seat above the airbox. Strange.
    under 5 layers of rotten tape I found this
    IMG_0347.JPG
    check out the soldering job on this!
    To make it worse the second connector with one black wire (the one I'm holding) for the CDI was so tired from abuse it fell off the wire. The wire doesn't stay clicked in.
    The connection is so intermittent that the bike doesn't start without a finger holding it down. And when it does run my tach no longer works:hack

    Now that I have found this I have some questions
    Why was this done?
    Why was this done so poorly??
    Would there be an easier way of fixing this without an entire new harness?
  19. CORNATO

    CORNATO n00b

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    Jesus...That's a hack job man. I don't know enough about these bike to help you definitively, but it should be pretty easy to fix if you have a working CDI. Most people are intimidated by wiring and electronics but its pretty easy. If you have a voltmeter I can possibly help you out, I can take my bike apart and test some leads and tell you what you should be getting where. If you want, but someone else probably has more expertise on these bikes.

    Don't freak out! It's looks bad but honestly these bike are pretty simple electronically.
  20. CORNATO

    CORNATO n00b

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    Jealous of those factory stickers man! Looks good, give her a once-over and start rippin!