2001 yamaha yz250 tranny issues

Discussion in 'Yamaha' started by FasterBlaster03, Aug 13, 2020.

  1. FasterBlaster03

    FasterBlaster03 Member

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    I got a 2001 yz250 and I just put a new top end, crank bearings, transmission bearings, shift drum bearings, and replaced all engine bottom end seal for crank, water pump, outputshaft, etc. I get the motor back together and it shifts through all it's gears fine. Sadly I think I'm going to have to crack it apart again because 1 gear is there but it wants to keep popping in and out of the gear but 2nd 3rd and rest up does not do this. I have had this motor apart and as far as I know there can be any issues with the shift drum or shift mechanism or shift pause. All those components seemed in tack and now wear noticable. I did not inspect the transmission like I should of. When we got this bike it was not running and the owner said he didn't want it he got it from a friend and he didn't have time for it. We paid 200 for it. My question is would you think there's worn out cogs on the gear? I wanna be led in the right direction in solving this. Any help is greatly appreciated. Thank you!
     
  2. Larry's Shee

    Larry's Shee Active Member

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    I can’t tell from your post, but this problem is while you’re riding it?
    Best suggestion I can give is research how to adjust the shift mechanism. The blaster has a specific process.
     
  3. FasterBlaster03

    FasterBlaster03 Member

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  4. FasterBlaster03

    FasterBlaster03 Member

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    I got the motor apart and the cogs are rounded out on the trans gear. I'm pretty sure there not supposed to be like that. I just boughtt new gear
     
  5. Slydog

    Slydog Active Member Technician

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    They should not be rounded.
    Also check fork. Tips for. Shiny areas that could indicate a bent fork also.
    Find out what years are interchangeable and look on flee bay
     
  6. FasterBlaster03

    FasterBlaster03 Member

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    Just got the tranny back together every thing shifts and rotates freely and I'm putting on the clutch cover today. Hope this solves the issue
     
  7. FasterBlaster03

    FasterBlaster03 Member

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    Also I replaced 1st and 5th wheel on output shaft with brand new OEM Yamaha parts
     
  8. Slydog

    Slydog Active Member Technician

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    Sounds good.fire it up:)
     
  9. FasterBlaster03

    FasterBlaster03 Member

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    Dumped fresh yamalube mix in her this morning.. good news and bad news, 1st gear did not slip but it started to shift weird. Could it be the shift fork the on the 5th wheel. It had no wear on the tips of the fork but lots of scoring toward the back of the fork. And on 5th wheel you can see the wear on the side of the teeth, obviously that's were the scoring on the fork came from.i would take pictures but blaster forum will not let me upload pictures the file is too large it says. Anyway would the fork be the issue? Before I had it together after I did the full rebuild it shifted perfect but had 1st gear issues, now now 1st gear issues but shifting issues. In the gear shifter I have to click up multiple times to get it to catch second gear and it does it not as much clicking right into first. Any help will be greatly appreciated. Thank youu
     
  10. Slydog

    Slydog Active Member Technician

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    Do you have a manual for the bike?.
    If not you should buy one. Look at a parts breakdown and see if you are missing a washer or something.some have a thrush washer on counter shaft between case and shaft. When trans is pulled out it can fall off.? Shift shaft is in good shape?. Not bent or binding. Contacts shift star correctly?
     
  11. FasterBlaster03

    FasterBlaster03 Member

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    May check my shift pause tomorrow I hope I don't have to change that fork. Also I replaced the shift shaft with a used one in great condition because old one was missing a washer and I could not find that specific washer so just ordered one with it. There can't be no issue with the shift shaft it worked fine after it was installed first time the motor was put together. And I've went through parts schematics on Yamaha parts house page. Looks like I'm not missing any other washers and spacers.
     
  12. FasterBlaster03

    FasterBlaster03 Member

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    Got the issue resolved did not have to split cases thank God!! Turns out the shift mechanism that goes on the drum ended up untiming itself from the dowel pin that holds it in place. Now the yz is a first kicker and rips like a bat out of hell!! And the way they ride, so smooth and its like the bike balences for you! We are about 700 in for a yz with a fully built motor! What a score!
     

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