1989 kx125 restoration master thread

[queen of spodes]

Clutch cover isn't wanting to sit down against the crankcase.   Traced it back to the shift shaft, which seems like it is sticking out a couple mm's too much.  The spring & white plastic collar move in a bit -- the shaft itself is what's binding the cover up. 

Anyone want to hazard a guess why?

[bens87braap]

ouch that sux someone will have an idea         are you using the original shaft?  Did you have to take much material off if u lapped that clutch case.   

[queen of spodes]

ouch that sux someone will have an idea         are you using the original shaft?  Did you have to take much material off if u lapped that clutch case.   

  Took next to nothing off.  Rubbed the case halves for only a few seconds, not for 30 minutes. Nothing bound up when putting the centercases together and the transmission works smoothly with the engine in a box and just manually rotating the crank & working through gears.

[Brute]

That little washer you couldn't find? Found it! 
I have no idea and have taken stuff like this apart, found nothing, put it back together and all is well with no explanation for it.

[queen of spodes]

I ordered a NOS shift shaft from CMSL (along with the spring and white plastic collar).   The current shaft's splines are a little rough, so I figured it wouldn't hurt to replace.

When I get time I'll pull the clutch pack and see what I can see when I pull the old shift shaft out.   

[queen of spodes]

Sigh of relief.  The metal inner collar that goes on the shift shaft slipped out of place.   Cases will close up nicely now.





Glad I ordered a new shift shaft though.. this one is buggered to hell. 



Front brakes are bled and tight.  Can't wait to see how they work with the steel braided line & RM125 master cylinder.


Rear wheel ready to be installed next:

[sandblaster]

Glad to see you sorted out the shift shaft.
The newer style master cylinders used a larger diameter plunger of 11mm.
They do provide a bit more braking with less finger pull.
I've even thought about making a 13mm plunger just for kicks.....

[jamex]

If you want more braking you need to do the opposite on the master cyl, go smaller or alternatively go bigger on the caliper or slave cyl pistons, works the same as sprocket ratios, hydraulic pressure ratio.

The smaller the actuating piston(brake lever) is with relation to the reacting piston(caliper or clutch), gives you more power on the reacting piston with less effort on the actuating piston, but less travel on the reacting piston & more on the activating piston, but seeing as a disc brake caliper only has to travel a fraction it does not matter so much & the gains on braking force with less hand effort are a big plus.

[sandblaster]

Ah... your right.... after I stopped and thought about it for about 2 seconds... I just kept thinking about the newer brakes having a larger master piston diameter.... but they also have a larger brake rotor diameter which would help offset the larger master piston diameter...
I also did some looking at caliper pistons and didn't find any with DLC.
Seems to me that slicker is better there.
A lot of poor performing brakes we find is the caliper seals and pistons being gummed up.
Disassemble, clean, reassemble, and bleed, works wonders.

[bens87braap]

glad to hear u got it sorted out

[queen of spodes]

Ah... your right.... after I stopped and thought about it for about 2 seconds... I just kept thinking about the newer brakes having a larger master piston diameter.... but they also have a larger brake rotor diameter which would help offset the larger master piston diameter...
I also did some looking at caliper pistons and didn't find any with DLC.
Seems to me that slicker is better there.
A lot of poor performing brakes we find is the caliper seals and pistons being gummed up.
Disassemble, clean, reassemble, and bleed, works wonders.

I half expect to rebuild both front and rear calipers, and should probably do that anyway.   Is there a decent writeup on oem-cycle or youtube?

[queen of spodes]

Rear wheel installed and brake bled.  Hub is a little dirty still.. not too worried, not putting $500+ more dollars in the toilet on new rims/hubs.  Maybe the next owner can get some black ones or something.   


Bike as it sits on Feb 11.   Airbox next, then maybe rear fender & silencer.

[sandblaster]

I half expect to rebuild both front and rear calipers, and should probably do that anyway.   Is there a decent writeup on oem-cycle or youtube?

I should do a write up but I'm sure there is one on youtube..
If you can't find one let me know and I will write up a quickie rebuild..

[queen of spodes]

Both front & rear feel tight tonight (vacuum bled) so we'll see how they do once the pads wear in a bit. 

[sandblaster]

Let me know...