YZ 250 Need Help Installing Transmission Shift Cam... how to align?

rob27ma
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7/16/2015 5:52am Edited Date/Time 7/20/2015 6:45am
I'm rebuilding my engine on my 2006 YZ 250, and I'm trying to install my transmission, but I'm having an issue with the shaft cam alignment. Once everything is installed I'm unable to shift and it seems everything gets stuck.

Does it matter what direction the shift drum is installed in the picture (see image)? Is it because the engine is not together yet... Will it shift correctly once the rest of the engine is put together?

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Paw Paw 271
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7/16/2015 5:57am Edited Date/Time 7/16/2015 5:58am
This photo seems to show 2 different shift forks riding in the same shift drum slot. That would cause the lock up.
Each shift fork rides in a different slot in the shift drum. Then you can rotate the drum to get into neutral and both shafts will spin freely when you have the forks in the correct slots in the drum.

Paw Paw
rob27ma
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7/16/2015 6:03am
This photo seems to show 2 different shift forks riding in the same shift drum slot. That would cause the lock up. Each shift fork rides...
This photo seems to show 2 different shift forks riding in the same shift drum slot. That would cause the lock up.
Each shift fork rides in a different slot in the shift drum. Then you can rotate the drum to get into neutral and both shafts will spin freely when you have the forks in the correct slots in the drum.

Paw Paw
I think it is just the angle of the image, here's a side shot.

Paw Paw 271
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7/16/2015 7:05am Edited Date/Time 7/16/2015 7:13am
In the top photo it looks to show that the left fork (c10) and the right fork are in the same slot. The second photo does not show the right fork.
Also the shift drum seem to be install upside down. The hole at the top of the drum should go to the bottom when installed, as I remember.
You see the little high hump in the shift drum in the second photo? That is the neutral hump.

Paw Paw
rob27ma
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7/16/2015 7:31am
In the top photo it looks to show that the left fork (c10) and the right fork are in the same slot. The second photo does...
In the top photo it looks to show that the left fork (c10) and the right fork are in the same slot. The second photo does not show the right fork.
Also the shift drum seem to be install upside down. The hole at the top of the drum should go to the bottom when installed, as I remember.
You see the little high hump in the shift drum in the second photo? That is the neutral hump.

Paw Paw
Thanks for the help! I'll double check that the forks are all in the correct slots, but it's the position of the shift drum that I couldn't seem to figure out whether it was right. Does it look like it's off by 180 degrees? or does it even matter what position the hole is in when I slide everything into the case?

The Shop

Paw Paw 271
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7/16/2015 7:52am
Yes the drum does seem to be out 180 degrees, as I recall. If it is installed incorrectly, the movement will be limited.
I feel the offset hole should be about 180 degrees from it's current location in the photos.

Paw Paw
RyanLester761
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7/16/2015 8:01am
I agree with Paw Paw about the shift drum being upside down. The hole (where the alignment pin will go) needs to be on the right side of the engine. Then, the shift star bolts on top of that. Don't forget your locktite!

I've always just set the shift forks in seperate slots, as stated above, and didn't worry about the orientation of the drum itself. I think it will only allow the fork pegs into the slots at certain rotations, so you should be good as long as they are all in a slot- for the most part.

Ryan
Paw Paw 271
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7/16/2015 8:38am
http://www.bikebandit.com/oem-parts/2006-yamaha-yz250-yz250v/o/m145162#…

Please note the orientation of the shift drum in this drawing in the transmission/shift drum section.
http://www.bikebandit.com/oem-parts/2006-yamaha-yz250-yz250v/o/m145162#…

I feel you have the correct end of the drum facing out, but it needs to be rotated 180 degrees. The outer hole should be down.


Paw Paw
rob27ma
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7/16/2015 10:51am
http://www.bikebandit.com/oem-parts/2006-yamaha-yz250-yz250v/o/m145162#sch530834 Please note the orientation of the shift drum in this drawing in the transmission/shift drum section. http://www.bikebandit.com/oem-parts/2006-yamaha-yz250-yz250v/o/m145162#sch530834 I feel you have the correct end of...
http://www.bikebandit.com/oem-parts/2006-yamaha-yz250-yz250v/o/m145162#…

Please note the orientation of the shift drum in this drawing in the transmission/shift drum section.
http://www.bikebandit.com/oem-parts/2006-yamaha-yz250-yz250v/o/m145162#…

I feel you have the correct end of the drum facing out, but it needs to be rotated 180 degrees. The outer hole should be down.


Paw Paw
Thanks for all the help, I'm going to try and finish re-assembling everything tonight and see how it goes.
Premixed112
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7/16/2015 11:57am
rob27ma wrote:
I'm rebuilding my engine on my 2006 YZ 250, and I'm trying to install my transmission, but I'm having an issue with the shaft cam alignment...
I'm rebuilding my engine on my 2006 YZ 250, and I'm trying to install my transmission, but I'm having an issue with the shaft cam alignment. Once everything is installed I'm unable to shift and it seems everything gets stuck.

Does it matter what direction the shift drum is installed in the picture (see image)? Is it because the engine is not together yet... Will it shift correctly once the rest of the engine is put together?

Well, this is strange but I think those are actually pics I posted onto thumper talk awhile back! Is that where you found them? And Ironically, the bike is an '06 yz250 also and I happen to be rebuilding it from the frame up right now.
rob27ma
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7/16/2015 12:08pm
rob27ma wrote:
I'm rebuilding my engine on my 2006 YZ 250, and I'm trying to install my transmission, but I'm having an issue with the shaft cam alignment...
I'm rebuilding my engine on my 2006 YZ 250, and I'm trying to install my transmission, but I'm having an issue with the shaft cam alignment. Once everything is installed I'm unable to shift and it seems everything gets stuck.

Does it matter what direction the shift drum is installed in the picture (see image)? Is it because the engine is not together yet... Will it shift correctly once the rest of the engine is put together?

Well, this is strange but I think those are actually pics I posted onto thumper talk awhile back! Is that where you found them? And Ironically...
Well, this is strange but I think those are actually pics I posted onto thumper talk awhile back! Is that where you found them? And Ironically, the bike is an '06 yz250 also and I happen to be rebuilding it from the frame up right now.
Yes, I did find these on thumpertalk looking for some directions this morning, thank you!

Mine is set exactly the same right now though, I just didn't have any pics this morning... do you remember how you were able to get this back together and working correctly?

I haven't been able to find any answer as to the hole alignment, and you're old post kept coming up in search but there was no answer to as whether this ending up working like this? Any advice would be greatly appreciate, I'm going to try and finish assembly tonight.
RyanLester761
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7/16/2015 1:36pm
I Googled "yz250 shift drum" and snagged a couple pics. I hope this helps. It is hard to tell the orientation (left or right case half) from your "borrowed" photos haha. But again, survey says threaded and pin hole toward right of engine and hole appears down-ish when installed correctly.

I really don't think you will have any trouble if the fork pegs are in each drum groove.




Paw Paw 271
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7/16/2015 2:28pm
Both ends of the shift drum have two holes. The center is only threaded on one end and that end goes on the clutch side. The second hole is for the dowel pin and that is pressed into the drum in most cases and does not just come out. So with that said the original photos show that the shift drum is facing the correct way in the cases, but is facing up in the photo and it should be facing down. In the up position the drum will not turn far enough to let the gears get into the proper positions to function.
Both gear shafts, all three shift forks and the shift drum have to be removed as a unit. Then the shift drum has to be
removed and reinstalled to the unit in the correct orientation and then the unit reinstalled. The end of the drum with the threaded center whole and the dowel in it goes into the case.

Paw Paw
slackinoff
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7/16/2015 4:41pm Edited Date/Time 7/16/2015 8:15pm
I Googled "yz250 shift drum" and snagged a couple pics. I hope this helps. It is hard to tell the orientation (left or right case half)...
I Googled "yz250 shift drum" and snagged a couple pics. I hope this helps. It is hard to tell the orientation (left or right case half) from your "borrowed" photos haha. But again, survey says threaded and pin hole toward right of engine and hole appears down-ish when installed correctly.

I really don't think you will have any trouble if the fork pegs are in each drum groove.




Right off the bat. Install the transmission into the left case, and also, one of your shift forks is upside down anyway.

Watch this video. You really don't have to use zip tys like he does. But he gives some great advise. https://www.youtube.com/watch?v=lOIWB4MP7yc

First. Not sure if this is a year thing, but in the third pic I have posted....the one from the above post.....the bearing I have circled in red is wrong. It should be an "open bearing" That bearing circled in red is actually a one sided sealed bearing and should be in the LEFT case half not the RIGHT ....I am pretty sure on this, as I just put together a 03 yz250 engine. And look at ken oconnors vid. That one sided sealed bearing goes in the LEFT case

Second, you can shift through the gears, but you will not be able to just by rotating the shift drum....you have to "jiggle" the forks up or down depending on what gear you are in.

Third, like I said, one of your shift forks is upside down. They should look like my first picture.....take a look at the numbers. From right to left it should be 5BE9 5BE8 5BE7 all those numbers facing you.



This is what neutral looks like.


[URL=https://imageshack.com/i/f0A2wiQCp][/URL
Paw Paw 271
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7/19/2015 8:10am
Did you get this worked out?

Paw Paw
rob27ma
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7/20/2015 4:54am
Did you get this worked out?

Paw Paw
Yes, I was able to get the bike back together over the weekend and everything seems to be working correctly so far. I think when I was originally trying to install the drum I was off by 180 degrees, so making sure the hole was in the right location did the trick.

Thanks again for all the help!

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