Author Topic: 02 - KX125 bottom end rebuild?  (Read 3741 times)

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Offline KXer

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02 - KX125 bottom end rebuild?
« on: June 24, 2011, 11:14:20 AM »
Just brought a KX125 from California (sea level) to Denver (6500') for my nephew.  Swapped in a new piston/ rings and top end gaskets.  Had to order new jets from sudco and told my nephew to WAIT to ride it.  Sure enough, the impatience of a 16 year old, didn't break in the new piston, and seized it. . . or so I thought.

After tearing the top end apart, found that the piston skirt on the exhaust side broke off and is now in pieces down in the crank.   :x :cry: I've done TONS of top end rebuilds from my old 250, to my new 500 to this 125 - but I've never had to split the cases.  Is there a chance I can split them, fish out the new piston skirt pieces, replace the gaskets and seals and put it back together (Without any major expense?)  What are the "Must" replace items when splitting the cases on a 125?

Thanks for your input.
Stupidity should hurt!

Offline DoldGuy

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Re: 02 - KX125 bottom end rebuild?
« Reply #1 on: June 24, 2011, 12:33:06 PM »
Crank Seals for sure & highly recommend the Crank Bearings, all is relatively affordable.


Find out why that skirt broke first!

DoldGuy
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Offline KXer

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Re: 02 - KX125 bottom end rebuild?
« Reply #3 on: June 25, 2011, 05:55:32 AM »
Find out why that skirt broke first!

My thought is that it got WAY too hot from being extremely rich and water in the radiators - not coolant.  I guess he was running it pretty hard and then it died.  I SHOULD have taken it home so he couldnt take it out. . . my bad.
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Offline Marco810

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Re: 02 - KX125 bottom end rebuild?
« Reply #4 on: June 25, 2011, 04:28:16 PM »
I would check the bore to make sure its within spec. Ive had a oval bore from wear on a bike and it took a toll on the skirt real fast