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Help 1990 Honda CBR250RR not running

Discussion in 'Honda 250cc In-line 4's' started by IDontLikeUsernames, Dec 24, 2018.

  1. IDontLikeUsernames

    IDontLikeUsernames Active Member

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    Hello all,

    I'm new to riding and working on bikes. When I got my license, I didn't want to go with the normal ninja 250s and such so I decided to import a CBR250RR from Japan with only 3994 km's. I live in the US so obviously parts are not available here so every time I need something, I have to spend an extra $30 on shipping from Australia or Japan and wait a few weeks for each part. When the bike arrived, it was not running, the choke cable was broken, the body was from a '94, and the brake pistons were seized. So far I cleaned the carbs and put in new float bowl gaskets, changed the oil, replaced the coolant, replaced the choke cable, fixed the brakes, replaced the fuel petcock valve, and cleaned and sealed the fuel tank. After putting everything back together and about fifty failed startup attempts, the bike started up. It was running rough and at idle it kept going from 500 RPM to 4,000 RPM. Also, the muffler was cold to the touch so I'm assuming it wasn't running on all cylinders (I'm no pro so I can't tell by sound). Unfortunately I couldn't test it for a ride because the tires are dry rotted and it was pouring rain. The next day, I tried starting it but it wouldn't start and kept backfiring. I decided to check the spark plugs and they were black and brown and smelled like fuel (The second and third pictures attached). I cleaned them and put them back for now but I'm not sure what to do. I figured I need to adjust the pilot screw to fix the AFR but I'm not sure what else to do.

    Thanks!

    upload_2018-12-24_0-11-7.png
    upload_2018-12-24_0-11-15.png
    upload_2018-12-24_0-11-25.png
     
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  2. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

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    New plugs required.
     
  3. IDontLikeUsernames

    IDontLikeUsernames Active Member

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    Thanks. I figured they would need to be replaced so I ordered some. Finally something that isn't coming from across the ocean.
     
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  4. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    Check out these things ...

    https://www.2fiftycc.com/index.php?...eads-spark-plug-configuration-inline-4s.8176/

    https://www.2fiftycc.com/index.php?threads/trim-your-spark-leads.8032/

    Did u check the inside of the tank? ... does it have an inline fuel filter?

    You may need to check that it has the correct main jets and the pilot screws are set initially to correct stock settings and that the carbs are synced

    Check each header to see if one or more are cold and not firing


    Have a look at Partzilla .... use the original part number as many parts are common to many Honda products apart from other bike models .. u can also try this if u have a local Honda dealer .... dont tell them the bike its for just the part number :D

    https://www.partzilla.com/catalog/honda/motorcycle


    https://www.2fiftycc.com/index.php?resources/honda-cbr250rr-mc22-parts-catalogue.64/
     
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    Last edited: Dec 24, 2018
  5. IDontLikeUsernames

    IDontLikeUsernames Active Member

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    When I first got the bike, I went through the service manual and checked as much as I could so I know the ignition coils are in the right spots. I have not trimmed them and I might try that.

    The first thing I did after getting the bike was remove the tank, drain it, and took it to a radiator shop to be cleaned and sealed. Apparently the bike had been sitting for 15+ years with the same gas so the tank was quite foul. It didn't have the filter on the petcock valve, but someone put a fuel filter on the fuel line from the valve to the carbs. I replaced that and bought a whole new petcock valve with the filter.

    It does have the correct main jets and in the correct carbs. I made sure of that when putting them back together. I did not remove the pilot screw so it could have been adjusted from factory. I will have to look into that. I'm assuming the carbs are not synced considering the bike sat for over 15 years and I just cleaned them.

    Unfortunately, I couldn't get it to start again. It just sputters and backfires every once in a while when trying to start it up. I did take a short video of it running but I'm not sure if showing that would help.

    Normally I look at CMSNL for parts because they have year specific parts with diagrams. I've bought parts from places like XCite Bikes and Motorcycle Spares Warehouse. I will take a look at Partzilla, though. Also, I did call my local Honda dealer and asked for parts but he said anything with "KAZ" in the part number is specific to the bike. If you didn't see already, I'm from the US so those parts never came over here and apparently, they can't even look up those parts or anything related to them. They don't even show up in the system.

    Here is the link to CMSNL if you haven't heard of them. They sell OEM parts. I mentioned them to the Honda dealer and apparently they bought every single spare part from a dealership that closed down by me. They went as far as sending shipping crates and trucks to load all the factory parts they bought.
    https://www.cmsnl.com/honda-cbr250rr-mc22-1990-l-japan_model14665/partslist/#.XCCFPlxKhPY
     
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  6. IDontLikeUsernames

    IDontLikeUsernames Active Member

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    In case you're curious, I attached pictures of the fuel I removed from the tank. It was pretty bad. 20181006_115819.jpg 20181006_115858.jpg
     
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  7. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

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    There are plenty of places to get parts from. Megazip.net is the one that I use, though expensive here in Australia, their service is great and shipping from Japan is usually within a week. There is also Impex which is cheaper but I haven't used them.
     
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  8. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

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  9. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    When you cleaned the carby's, were any of the jet's blocked?, eg main jet's, and especially the pilot jet's ?
    You might want to check where the idle mixture screw's are set at now, eg screw them in gently till they stop and count how many full turn's they were at.
    Then unscrew them fully and take them out, now clean out the bottom of the thread's where each mixture screw screw's into, there should be a small hole at the bottom that goes through the carby body into the main bore, if this hole is blocked or partly blocked you'll have lot's of trouble starting it.
    You can use some fishing line to poke through the hole's so you don't damage anything.
    Once you know the hole's are all clean, refit the oring, washer and spring then screw the mixture screw's back in to where they were set at previously eg 2.5 turn's out from fully closed.

    Sometime's you can clear a blockage by placing the palm of your hand over the intake side of the carby/s and crank it over a few time's, the palm of your hand should get wet with fuel and be sucked toward's the carby each time you crank it over.
    Try starting it and see if it make's a difference, if it does the carby's probably need a thorough clean out


    I doubt that the coil lead's would need trimming if the bike has only done 4000km's
     
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  10. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    I think sitting for that long , just about everything and anything is possible ... especially if the conditions it sat in are questionable .. I bet it wasnt in a climate controlled storage unit :lolsign:
     
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  11. kiffsta

    kiffsta Senior Member

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    I’d it say if it satlong. I would guess that fuel has dried up in the carbs , my 2c is to find some threebond engine conditioner , similar product in the us is Seafoam and strip and clean your carbs.

    I would remove the air fuel mix screw and your Pilot jet and make sure the passage between them is clear. By spraying Seafoam down the air fuel mix screw hole, It should come out of the pilot jet hole and one of the brass air holes in the front face of the carb. Failing that remove all your jets and air fuel mix screw and find someone with an ultrasonic cleaner.

    Great looking bike , you are going to love it.
     
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  12. IDontLikeUsernames

    IDontLikeUsernames Active Member

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    I think most of the jets were blocked. The larger mixture screw was screwed all the way in for all four carbs so I put them back as they were after cleaning. It looked like the mixture screw screwed into another screw that could be adjusted (if that makes sense). Essentially, the mixture screw was screwed all the way into another thing that could be screwed in and out of the carbs. I would take a picture, but I can't right now.

    I used compressed air and a sewing needle which seemed to work. I have heard people say don't use a sewing needle but I was extremely careful and only used it if the compressed air didn't work.

    I checked the coils without trimming them by using a flashlight and magnifying glass. They looked very clean.

    I think the bike was in a climate controlled warehouse for a while. The guy I bought it from exports Japanese racing bikes all over the world so he has nice building full of them. I did some background research before buying the bike so I looked up the company and building.

    The fuel was dried in the carbs and there was a ton of white and black gunk in the float bowls. I used carb and throttle cleaner to clean the float bowls and screw holes but I did buy Seafoam and put the bottle in the tank when I got the bike started.

    I really hope I love it. I spend a lot of money for this thing. :D

    PS
    Merry Christmas everyone! I know it is late but I was busy over the holidays so I couldn't respond.
     
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  13. Frankster

    Frankster Grey Pride...Adventure before Dementia Staff Member Premium Member Ride and Events Crew

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    This is what your mixture screw should look like (ZXR mixture screw pictured). CBR and ZXR both use Keihin carbs.
    Mixture Screw.jpg
     
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    Last edited: Dec 28, 2018
  14. kiffsta

    kiffsta Senior Member

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    Set your mix screws 1 3/4 turns out , then tune from there , if all your jets are clear then she should start and run.

    Check your carb insulators for cracks, they do perish over time
     
  15. IDontLikeUsernames

    IDontLikeUsernames Active Member

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    I have a new update with the bike.

    Last week the bike started after I sanded the spark plugs clean and checked the gaps while I waited for the new ones. Idle was a bit rough staying around 2k and spiking to 3.5k every once in a while but it was running on all cylinders. I ended up taking it for a quick ride around my neighborhood to test it out and it rode well. Unfortunately it was about midnight and I don't have a title, registration, or insurance yet so I kept it quick and decided to wait until the next day so I could actually see to try and ride it around.

    The next day, after doing nothing to the bike, it started up right away then after letting it sit for about two minutes to warm up, it cut out. I tried for the rest of the day to get it started again but it kept backfiring when cranking it over.

    A few days later I got the new spark plugs and put them in but it still wouldn't start. It would get up to 500 RPM then immediately die the first time I tried starting after letting it sit, then after that it would crank for a bit and backfire. I decided to take it apart and remove the carbs again after putting Seafoam into them. The Seafoam came out of the carbs a dark yellowish/greenish color. I removed all the jets and they were clean. I then removed the mixture screws (which were set to 1 -3/4 revs like they should be), cleaned them off and set them back to 1 - 3/4 revs. One of them was missing the o-ring.

    Does anyone have any ideas of what to troubleshoot next? I talked to a few people who work on bikes and they said at this point the only thing they can think of is an electrical problem. I replaced the battery and it is charged so I know it isn't a battery issue. One thing I did notice was that the turn signals only work every once in a while. If wiggle the wire bundle coming out of the switch block on the handlebar it sometimes helps.

    Also does anyone know where I could buy just the o-rings for the mixture screw and quality insulator bands? The mixture screw is apparently the same for many Keihin carbs so Honda dealerships near me have them, but I can only buy the combination of screw, spring, washer, and o-ring for about $20. The best deal for OEM insulator bands I found was about $65 for all four but I was wondering if anyone knew where to get them for cheaper.
     
  16. Frankster

    Frankster Grey Pride...Adventure before Dementia Staff Member Premium Member Ride and Events Crew

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  17. kiffsta

    kiffsta Senior Member

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    Buy only genuine carb insulators

    https://www.xcitebikes.com.au/16211-kaz-000/

    @XCite Bikes will hopefully ship to you

    If I was you I would be looking for someone with an ultrasonic cleaner and remove the top caps and slides as from the top of the carbs and then remove the float bowl, floats and jets , then pull the af mix screws and get them cleaned

    Sounds like the Seafoam is helping, but I wonder if there is more blockages.
     
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  18. kiffsta

    kiffsta Senior Member

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    Had any luck with the bike ?
     
  19. IDontLikeUsernames

    IDontLikeUsernames Active Member

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    Kinda. I cleaned the carbs as best I could then put them back on to try and start it. It wouldn't start so my next guess was that there is a spark issue. I used some starter fluid and sprayed it directly into the carb air intake while trying to start the bike and nothing happened. I tested the coils, spark unit, and wire connections to them with a multimeter and they were fine. Once I put the wires and spark unit back on, I used starter fluid again and the bike started right up. After putting the air intake and fuel tank back on, the bike started and ran for about 5 minutes with and without choke. The RPMs at idle were good and stayed at about 1,500 RPM. The instant I gave it a bit of throttle, it died. I couldn't start it again after that. I think there is a spark issue. I haven't had time to work on it since then but my next guess is the pulse generator is bad or the wiring for it is loose somewhere.

    I think I'm gonna contact a race shop near me once they're actually open. I've done the best I can given what I have for cleaning the carbs and checking the wiring so now I'll let the professionals take a look. Plus, I'm back to work and school so I dont have a ton of time to deal with it.
     
  20. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    If it is electrical it is far more likely to be the TCI unit rather than the pulse generator. Fried Reg-Rec units damage the TCI when they overcharge. Chinese company Liaxanda make replacements https://www.lixianda.com/products/honda/
    Does sound like a fuel blockage though.
     
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