125 89 kx 125 coolant oil mix disaster

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viseversa101

So last week I picked up an 89 kx125. Long story short it died and I noticed milky white goo seaping out by the kick start.
Today I pulled the head and found the bottom head gasket had been leaking quite some time the studs were pretty rusty. And a assumed it to be a bad gasket. The piston is shot and going to be replaced also. Total top end overhaul. However I'm scared of the goo inside the case. I mean sticky goo too.

Looking for some advice here to avoid redoing this again?
Do I check the impeller and gaskets also?
Am I going about this the right way?
How do I properly flush the case? Or do I need to open it?

ANY advice is much lyrics appreciated in advance as this is my first bike. I've already picked up a manual and have been thru it inside and out up to chapter 8 thus far.
 
2strokesteve89

2strokesteve89

Yup, my first thought was water pump seal as well. But now is a good time to go thru the new to you bike with your manual(by the way you don't realize how many come on here and resist acquiring a manual at all costs, nice to see somebody doing it right) and freshen her up with a new piston and rings, take a look at the clutches as coolant is pretty tough on the friction material. And like Mikey said clean out the cases with kerosene or diesle. After you get her running and broke in change the oil again and you should be good to go.
 
Mihylo33

Mihylo33

timoyz:
I guess I'm just anal. On that old of a bike, I would want to look at everything. Besides I don't feel it's really my bike until I split the cases.:wave:
Click to expand...

I'm right there with you Timo. New bike same day new manual. Pull the jug and at the very least replace the top end. :thumb:
 
V

viseversa101

Okay. Next question. Would be the cylinder isn't the greatest. The piston was torn up I know it needs hones if not bored. If I bore it what do you recommend. And do you combo a high comp head gasket with an oversize bored piston?
 
V

viseversa101

1462293167181-278242317_zps3g4fqfq7.jpg
Once I get home. Currently at work
It'll be about 5 hours from now
 
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O

ossagp

Lots of things to check for there. I would like to see the top of the piston, but it looks to me like you were getting coolant into the cylinder. you have pieces broken off from coolant collecting in the cylinder and doing two things: one, the hot piston crown gets brittle from the coolant hitting it at the hottest point (right at the exhaust port side), then you get a hydraulic locking action as the liquid can't escape compression fast enough. on top of that you have your own form of 'water injection' working there. google that for airplanes if you are curious and unfamiliar.

that rig was sent from the factory with what kawasaki termed and electrofusion cylinder. as such it can't be bored, but may have already been sleeved so that it possibly can (i say possibly because it may already be at max.)

so lots of things to check, and i agree that your water pump seal is out.
 
Mihylo33

Mihylo33

I'm with ossa on this. Best place to send that cylinder is to Powerseal USA in Pa.
It looks to be a plated cylinder. A cheaper rout would be to have it steel sleeved which I am not a fan of doing. The head may also need to be cut and decked.
Keep us posted.
 
M

MADMATEMATT

you wont be able to "hone" or re sleeve your bore on that model mate(it doesnt have a sleeve as standard. your options are source a new block(try partzilla.com, but pretty sure you are out of luck there), or for around $300 you can get it re nickle plated which will be better than original bore. try a nakamura piston set, i have run them in kx's and they last ages!
 
2strokesteve89

2strokesteve89

Actually sleeves are available for almost anything, but like Mike said I'm not a fan of sleeving a cylinder that started out plated. One of the main reasons is a sleeve will not disapate heat like a plated cylinder does,the possibility of a cold seize is greater with the sleave. and really what's not to like about getting up to 3 top ends for each replate?
 
SRAD97750

SRAD97750

Moderator
Staff member
Two facts here have me puzzled. (Last two top ends I did were an 89 KX 125 and 86 yz250. I am quite familiar.)

I can see what appears to be a steel sleeve at the face of the cylinder as well as at the ports. The KX I did had a sleeve for whatever reason. $50 bore and a $75 piston kit, kid is riding hard again.
Try a magnet on that bore, if it sticks, do some measuring to see if an oversized piston is available and room to bore.

The other bit is the second land on that piston. I thoroughly searched every piston available for the 89 KX125, and 100% of them were single ring. Not sure where they found that one, but it also plays into my thinking this has a sleeve already.
-BIG DAN:thumb:
 
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ossagp

SRAD97750:
Two facts here have me puzzled. (Last two top ends I did were an 89 KX 125 and 86 yz250. I am quite familiar.)

I can see what appears to be a steel sleeve at the face of the cylinder as well as at the ports. The KX I did had a sleeve for whatever reason. $50 bore and a $75 piston kit, kid is riding hard again.
Try a magnet on that bore, if it sticks, do some measuring to see if an oversized piston is available and room to bore.

The other bit is the second land on that piston. I thoroughly searched every piston available for the 89 KX125, and 100% of them were single ring. Not sure where they found that one, but it also plays into my thinking this has a sleeve already.
-BIG DAN:thumb:
Click to expand...

Myth busting here. Magnets stick to some of the plated cylinders. seems they have steel in just about all of them. honda for instance; the two strokes i tried it on would hold a refrigerator magnet vertical and horizontal. while we are talking magnetic hondas : my crf came with stainless exhaust valves. the quality is good enough that a magnet won't stick. however a magnet stick to the copper beryllium seats. (so you need to remove the valve if you want to see if i am telling the truth.)
 
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