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2000 KX 250 enigne case compatibility?

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Hello there. 

 

I will inform you honestly of the situation so you can understand where we have come unstuck and please no hate. I fell bad enough already. Thanks. We have carried out a full rebuild of this engine, top and bottom, including transmission bearings.

We have a situation in our workshop where we are in need of both the left and right hand cases for a 2000 KX 250. What has happened is we lapped both the inner sections of the cases on our lapping table as both cases were showing signs of distortion. We are not 100% sure how much has been removed but I am guessing it's about 4 thou, I.e 2 thou off both sides. (0.100 mm) The issue is that our client s experiencing problems with it now being difficult to select neutral and when shifting from 1st to second it sometimes selects neutral and not second. there was no problem with shifting before we did the work. I have checked the end float from the output shaft and it was tight when shifting so we removed about 8 thou off the output shaft bush and this has freed up the output shaft but it is still suffering from the same shifting issue. I could go back in now and remove 8 thou off the shift drum as I am sure that is the only other place it could be binding as the main shaft and end float but I think it is best to quit it now and replace the cases. I know that none of this sounds ideal but I am publicly admitting a mistake and that's a difficult thing to do and if anyone can offer me advice or tell me what years that are compatible with the 2000 model as we will find replacement cases and fit them.

 

Kind regards

 

Geoff.   

 

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Man, the 1999-2000 kx250 was notorious for hitting neutral during the 1st to 2nd shift. Mine does the same thing, even before I lapped my cases. I did help it a lot by polishing the shift drum channels, but to me it just sounds like a normal kx250 lol. You can help it a lot by using a 2002 shift stopper, because it has a larger diameter stopper wheel and it stops a lot of the false neutrals. Try that for $10 on e*ay before you buy new cases.

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You can use 99-01 cases by the way. 2002 cases have a larger diameter crank bearing.

Thanks for all your info Rancer420. I have new cases on the way and we will swap everything over so I can confirm weather or not it's the case lapping causing the issues. Also we may try the groove polishing. Do you know if the changed the stopper spring also on the 2002??

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Yeah, the stopper had a larger wheel and a stiffer spring. They're on ebay all day long for $10. I polished the shift drum channels, dogs, and the end of the shift shafts that actuated the drum assembly. I used a Dremel polishing wheel and compound. Before assembly I LIGHTLY coated all of the polished surfaces with grease then wiped it off, leaving only a very thin residue on the sliding surfaces. A few experiments I tried beforehand made me feel that the thin grease film made a much slippery surface after the oil in the tyranny coated it. My tranny is literally the slickest, best shifting bike I've ever ridden-it shifts under full power without the clutch, and is smooth as silk pajamas. I very, very occasionally miss the 1st to 2nd shift again and find neutral, but it's about the same amount that it would be for any other bike at this point. Hope you fix your issue!

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I would assume the stopper was the same as the 01. Just buy an 01 stopper if in doubt lol. I also polished the metal slugs that are on the end of the drum (that silver slugs that the shift shafts assembly push on to move the drum up and down.

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Hey Rancher. 

 

Thanks very much for all the information. I will make sure I come back to you and let you just how I got on. 

 

Kind regards

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Just one other quick question?????// Did you remove any material on the shift star ramps just before and after the neutral position?

I hope that makes sense.

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I've heard of people filing down the neutral ramps so that it's harder to hit a false neutral while riding (it also makes it harder to find neutral in general), but I never did anything to mine.

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