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Discussion Starter · #1 ·
OK, I need help now.

This CB200 shifting problem is kickin' my butt.
I've had it apart three times now, can't seem to get it to work right.

It jumps out of 3'rd/4'th gear, and I can see exactly why as I work it through the gears on the bench.
Just seems like the gears are not synchronized - the shift drum pushes the gears over well enough, but the lugs on one gear don't match up with the holes on the other gear - so it stops just short of complete engagement. Then jumps out under load.

I've tried three different fork drums and fork sets (all appear good), two shift shafts, two transmissions.
Everything seems to be within specs and properly assembled.
The shift stopper/roller thing is brand new (an amazing EBay find).

Any ideas at all ?? - Wifey is killin' me on this......
 

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Sensei
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Bill, I had one (a 175) that was doing that....turns out one fork tine was a smidge off perpendicular and did not "continue" force to hold the gear in....A worn labyrinth groove or follower pin can also cause that condition.... As can a bit of junk preventing the drum from fully seating in enough (extra shim washer?)...... None of those conditions sound like anything that someone with your experience would overlook, so I'm at a loss too.... :( Steve
 

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Discussion Starter · #3 ·
I'm pretty sure the shift stuff is ok - I can feel that the fork is trying to move the gear all the way, but the gear next to it (which it engages) is never lined up properly to accept the lugs.
It takes far too much twisting of both shafts to allow them to line up right.

I'm at a loss, not sure how a "constant mesh" (and therefore synchronized by definition) tranny can get "out of synch" like this.......
 

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Sensei
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Two silly questions... Are you testing dry?.....They rely on the oil film to work (synchronise) properly... (some assembly lube is too thick)
Are you spinning the countershaft when shifting ?....Almost has to be for every gear but N to 1 going up and all of them going down (in my experience)
That's all I got........
 

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Discussion Starter · #5 ·
66Sprint said:
Two silly questions... Are you testing dry?.....They rely on the oil film to work (synchronise) properly... (some assembly lube is too thick)
Are you spinning the countershaft when shifting ?....Almost has to be for every gear but N to 1 going up and all of them going down (in my experience)
That's all I got........
No, it's oily, not dry.

Spinning the counter by itself doesn't remove the misalignment, because the two gears that won't synch up are both on the countershaft.

Maybe I'll take some pictures .............
 

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Sensei
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Yeah Bill, I got that, but when in the oil bath, the layshaft's (idler)gears resist turning proportional to their diameters and the "gear speed" it was spinning, and "sync it".... They are almost never "smooth" in operation unless both shafts turn at differing rates...(at least for me....)
 

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Sensei
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Better explaination.... The layshaft is "stopping" and/or slowing down because the clutch just released pressure on it... The countershaft is still spinning close to whatever speed it was going (driven by the rear wheel) albeit slowing slightly, and the differences in the two shaft's spin speeds either speed up or "drag" down one of the gears (the idler with the holes you are trying to mate) enough that the slider gear tines will swipe/slide to the holes and drop in....... You'd have to "match" the speed differential of the two shafts manually to have exact perfect alignment (which is nearly impossible) to have the slider tines go directly into the center of the idler holes every time.... If/when they do go in, and if there is enough "undercut" on the engaging parts, it will stay in gear......

( Bill, I KNOW you understand this, but the newbies "looking-in" might want a more succinct explaination.... ;) Steve)

I'd just assemble with the best condition 3rd and 4th gear pairs on both shafts, and button it up.....
 

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Discussion Starter · #8 ·
66Sprint said:
I'd just assemble with the best condition 3rd and 4th gear pairs on both shafts, and button it up.....

Yeah - done that twice now, still won't work right......

and this thing is a giant PIB to get in/out of the frame, already torn up some frame powdercoat.
 
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