[1mach1]

Fellas, 99 KX 250 with some hard hours, no gear/shifting problems, but heard some grinding screech noise, engine died. Pulled top end, cylinder/piston fine. Pulled motor out, top end off, still spins with some noise/light screeching telling me bearings are going. Piston rod feels a little loose as well.......

Any thoughts on the bottom-end engine rebuild? I will be inspecting all gears and parts to ensure no broken, cracks, excessive wear, etc. and replace. General question is related to what bearings should be replaced, parts that might need to be machined, any parts that should be replaced every time engine is split even if look good, or any general heads up this first time 250 bottom end fix-garage mechanic(me) should know about? This may be an excellent thread for future viewers as well.

Thanks.
Marc

 

[QKENUF4U]

crank bearings or big end rod bearing is gone from the sounds of it . if its the rod bearing then your gonna either have to buy a crank assembly or have yours split and rebuilt

 

[1mach1]

Thanks for the reply. I am going to split the case and replace the bearings and put in a new crank assembly (if needed). I will post any interesting things/problems I run accross....

Marc