2003 Cr125 grinding noise

[xxRMxx]

I was riding my cr home one day and it started making this weird grinding and when I heard it I shut it off and pushed it home I found out later it was dry on oil because I ran atf in it and it evaporated or something cuz it was dry and it never leaked so I tore it apart but haven't spilt the cases yet and haven't found anything wrong so far the clutch is good piston a Lil scarred but cylinder is fine gonna a new top end I don't have a flywheel puller so can't go any farther yet but I shifted it through the gears and it seamed fine any ideas on what's wrong???

[GustavMiller]

Could be a bearing in the trans section. Your pre mix lubes the piston. The "oil" does the trans. Your ATF didn't evaporate. It either leaked out of the engine. Or it leaked through a seal and was burned away due to combustion process.

Edited August 4, 2014 by GustavMiller

[xxRMxx]

My crank seal on the clutch side was ate uo

[xxRMxx]

And my plug is coal black

[zotis777]

So replace what's worn and reassemble.

P.s. If you burned away your ATF check your steels for blueing/warpage