1989 kx125 restoration master thread

[queen of spodes]

Second time was a charm. 

Didn't make the lip of my second tool as wide.  put a little more heat around the bearing (and on the back side of it).




Now to clean these case halves up a little more.

[queen of spodes]

What caused (causes?) the pitting I'm showing on one of my case halves?   Is this something to worry about?  None of the divits are very deep, and the case thickness is not at all in danger.   

Curious to know what these are exactly, and if it is something I need to be especially concerned about.

[Foxx4Beaver]

that could be a combination of/from corrosion...and just plain ole porosity from a s**ty cast from the factory....if it's held up this long, I wouldn't be too concerned....providing the bearing journal is still good.

[sandblaster]

Looks to me like there was a bit of water that sat in there for a while.
As long as the mating surfaces are good, you should be ok.

Using good glass media in the Vapor or water blaster is the way to go.
If the metal is really bad you will have to glass blast it first.
The Vapor or water blaster will remove the impregnated media so I have been told.
I will of course test that theory when I get mine 

[queen of spodes]

as rare as parts are for this old bike, I probably won't use it as a guinea pig.    From all I've read, the glass media will partially lodge itself in softer metals (AL) and work its way out later.. causing cylinder scoring, premature wear, ect.    Maybe the water/glass slurry makes the difference.. maybe.    I guess one way to test is to blast a broken case, then literally grab a microscope to check for evidence.

[queen of spodes]

An airplane mechanic acquaintance of mine had this to say about the photos above:

Motorcycle parts are notorious for casting pits, so my guess is that's what this is. You can use 80 grit by hand, maybe 120 with Dremel on slow, to evenly remove material and see if pits diminish. If you start seeing more then STOP as it's definitely casting voids. If you manage to get it cleared up with the 80 or 120 then finish out with progressively finer grits until the finish you want. You can apply an alodine or similar solution to further protect the surface.

[Foxx4Beaver]

yup...porosity.

[queen of spodes]

I'm less concerned about how the inside of the crankcase looks.. don't need it to be purty.   but do want to stop the corrosion if it is ongoing.

[sandblaster]

as rare as parts are for this old bike, I probably won't use it as a guinea pig.    From all I've read, the glass media will partially lodge itself in softer metals (AL) and work its way out later.. causing cylinder scoring, premature wear, ect.    Maybe the water/glass slurry makes the difference.. maybe.    I guess one way to test is to blast a broken case, then literally grab a microscope to check for evidence.

Yep... that's what I'm gonna have done.
I know someone who knows some one at the U of O.
Also, I have the backyard testing method...
If when using this....



It does this...



And when you rub your fingers together it is gritty....
That is bad  

I spent several hours getting all that gritty stuff out of mine after bead blasting...

[sandblaster]

I'm less concerned about how the inside of the crankcase looks.. don't need it to be purty.   but do want to stop the corrosion if it is ongoing.

It's not going to corrode any further as long as you don't mix water with your fuel.

[queen of spodes]

Think I'm going to bail on this right side engine case.   Crank seal surface is corroded - see the big hole where the tool tip is?  Not sure I want to chance this engine on a suspect seal surface.  



Ugh.  Getting burned out with the nonstop hiccups and unexpected expenses.  

[queen of spodes]

While the original matched case is at a shop being repaired (oil drain plug collar broken), I'm gathering stuff I'll need to assemble the lower end.

Kawasaki doesn't offer 57001-1174 anymore but there is an alternate on Ebay:
http://www.ebay.com/itm/CRANKSHAFT-JIG-REPLACES-KAWASAKI-TOOL-57001-1174-TO-HELP-YOU-INSTALL-CRANK-MOTOR-/200888811855

Before I dump $80 on this tool I'll likely only use a few times in my lifetime, do I absolutely need this tool or can I make something for cheap that does the same thing?   I don't want to mess with the crank balance, so if I have to get it, I have to get it.  



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Setting out bottom end bits on the workbench so I can go through what I have, and see what needs to be replaced. Obviously the broken gears in the pics have to go. 

[motojason]

Before I dump $80 on this tool I'll likely only use a few times in my lifetime, do I absolutely need this tool or can I make something for cheap that does the same thing?  

No, you do not need that tool. I don't like the idea of pressing on the crank to assemble the bottom end. That tool only acts as a crank spacer to keep the flywheels parallel while you press the cases onto the crank. I put my crank in the freezer and my cases in the oven. Then I use some threaded plumbing fittings from the hardware store to pull the crank into the cases if it needs some additional tweaking. Use 1-1/4 to 1-1/2" black iron couplings and 3/4 reducer. Use the fittings as a spacer between the crank's ends and the case, use washers between spacers and nut on the crank's primary side or bolt on the ignition side. When you tighten the nut or bolt onto the crank it draws it into the case without putting stress on the crank pin. The plumbing parts and big washers cost me about $6-7 at Ace and I have used them on KXs, YZs, and CR cranks with no problems  

[motojason]

And... Awesome job on the restoration! That is a great bike and its nice to see the care and quality that you are putting into the project. What do you plan on doing with it when you are done? 

[dinkyguitar]

Before I dump $80 on this tool I'll likely only use a few times in my lifetime, do I absolutely need this tool or can I make something for cheap that does the same thing?   I don't want to mess with the crank balance, so if I have to get it, I have to get it.  

I didn't use any special tools either when I closed my cases on my 87 KX250.

I used a barbecue to heat my cases to about 170 deg, and also froze the crank.

Once the case heated I quickly got the crank and dropped it in. I had to use a piece of 2x4 to tap the crank in because the coldness of the crank hitting the heated case will sometimes stop it from sliding in.

Then, I quickly applied yamabond to the case, got the other half of the case and installed it.....you have to work quickly, but it can be done. Just have everything ready and planned and make a dry run first.

With heat and freezing parts, you can put or removed just about every bearing in the motor without buying special tools.

dinky,