1998 kx 250 shift drum changer

[rocko]

I hope someone can help me on this problem. My sons shift drum changer holder lately has been breaking off the 2nd gear holder pin and I have no idea why. Does someone have an idea on this problem as I am not even sure where to start. Any ideas would be welcome. Thank you.

[sandblaster]

Hello Rocko.
Welcome to the site.
This site is filled with knowledgeable good guys wearing White hats and I'm certain someone has ran into this problem before and can give you some good points.
If you can, feel free to post pics of your ride and tell stories as to how you decimate the 450's on your 15 year old 2K.
We like it a lot 

[sandblaster]

Is this the part that keeps breaking?

[rocko]

Yes it is. The pin will break off when shifting from 1st to 2nd, the last time under very  soft shifting.

[sandblaster]

I've never seen this so I can't tell you what is causing it.
PM me with your mailing info and I'll send you some parts to try.

[Motorrad]

Hey rocko     welcome to the site.

I have a few ideas of what it could be.   Ill post those up later today.

Busy shampooooooooing the carpets right now        Honey do list takes priority.   

[rocko]

Yes it does. No hurry I will watch for your post, Thank you

[Motorrad]

do you have a camera?   and post some pictures.

MARKS tell lots of storys.

im thinking the "fork" what I call it is bent or somthing..

[rocko]

I will get it tore down this weekend he has a race coming up in a couple weeks. I am my sons pit crew but being a disabled dad sometimes it takes me a bit and I will need his help getting his motor out. When I do and get it tore down I will get pictures up for you to see, if I can figure how to put them here. I figure the shift drum or shift fingers were the problem but just not sure and was looking for some imput. Thank you

[sandblaster]

If you have a hard time posting the pics, email them to me and I'll post them for you.

[rocko]

Heres what I found. With my glasses on and my clymer service manaul open on the bench beside me, and the spec page open I visually checked and measured the service limits on everything. While everything was well within limits I did find small flat areas on the shift fork guide pins, and more concerning a divit in the shift drum groove at the spot, when put together, where the pin breaks off. The shift drum does not rotate smoothly in this area. So I will call sandblaster and get these parts and see if this is the cure, I hope so. I would like to hear anyones thoughts on this, do you think this wear could be the cause of my problems or not. I will try to post a picture of the shift drum in the picture you will see a white mark and below is the divit on the wall of the groove. Thanks guys

[Goat]

The walls of the groove should be smooth. It's hard to see the divit in the pic. Are there abnormal wear marks on the pin that rides in the groove?

I had something similar to this issue when I was a kid. It was a 79 yz125. The pin on the shift fork somehow wore a couple different angles and gouged the drum. Mine didn't break parts it just wouldn't shift.

[rocko]

Thank you. Sandblaster sent me a different shift drum and shift forks they are in much better condition than our old ones. My son rode it and says it shifts smoother than before so we will cross our fingers and take it to the first race of the season and see how it goes. I want to thank everyone who helped me with this hopefully we have it fixed. Thank you.

[sandblaster]

Hope it all works well 

[Friar-Tuck]

What a guy,
SandBlaster To the Res-cue...Sandblaster To the rescue....Go SandBlaster Go SandBlaster!!!!   
        (Sung to the tune of  "Jim Dandy to the Rescue"...) 
  T\o/